31140216 has 24 divisors (see below), whose sum is σ = 84338280. Its totient is φ = 10380048.

The previous prime is 31140191. The next prime is 31140233. The reversal of 31140216 is 61204113.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (24).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 216180 + ... + 216323.

It is an arithmetic number, because the mean of its divisors is an integer number (3514095).

Almost surely, 2^31140216 is an apocalyptic number.

31140216 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

31140216 is an abundant number, since it is smaller than the sum of its proper divisors (53198064).

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

31140216 is a wasteful number, since it uses less digits than its factorization.

31140216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432515 (or 432508 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 31140216 is about 5580.3419250078. The cubic root of 31140216 is about 314.6109785665.

Adding to 31140216 its reverse (61204113), we get a palindrome (92344329).

The spelling of 31140216 in words is "thirty-one million, one hundred forty thousand, two hundred sixteen".