31004240220 has 36 divisors (see below), whose sum is σ = 94046195880. Its totient is φ = 8267797344.

The previous prime is 31004240131. The next prime is 31004240237. The reversal of 31004240220 is 2204240013.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×31004240220² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 31004240193 and 31004240202.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 86122710 + ... + 86123069.

It is an arithmetic number, because the mean of its divisors is an integer number (2612394330).

Almost surely, 2^31004240220 is an apocalyptic number.

31004240220 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31004240220 is an abundant number, since it is smaller than the sum of its proper divisors (63041955660).

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

31004240220 is a wasteful number, since it uses less digits than its factorization.

31004240220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172245794 (or 172245789 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 31004240220 its reverse (2204240013), we get a palindrome (33208480233).

The spelling of 31004240220 in words is "thirty-one billion, four million, two hundred forty thousand, two hundred twenty".