31420320 has 96 divisors (see below), whose sum is σ = 100554048. Its totient is φ = 8245248.

The previous prime is 31420313. The next prime is 31420327. The reversal of 31420320 is 2302413.

It is an interprime number because it is at equal distance from previous prime (31420313) and next prime (31420327).

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 31420320.

It is not an unprimeable number, because it can be changed into a prime (31420327) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31672 + ... + 32648.

It is an arithmetic number, because the mean of its divisors is an integer number (1047438).

Almost surely, 2^31420320 is an apocalyptic number.

31420320 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31420320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50277024).

31420320 is an abundant number, since it is smaller than the sum of its proper divisors (69133728).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31420320 is a wasteful number, since it uses less digits than its factorization.

31420320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1062 (or 1054 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 31420320 is about 5605.3831269593. The cubic root of 31420320 is about 315.5514653382.

Adding to 31420320 its reverse (2302413), we get a palindrome (33722733).

The spelling of 31420320 in words is "thirty-one million, four hundred twenty thousand, three hundred twenty".