31897152 has 168 divisors, whose sum is σ = 108728256. Its totient is φ = 9082368.

The previous prime is 31897141. The next prime is 31897157. The reversal of 31897152 is 25179813.

It is a tau number, because it is divible by the number of its divisors (168).

It is a super-2 number, since 2×31897152² = 2034856611422208, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (31897157) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 108718 + ... + 109010.

It is an arithmetic number, because the mean of its divisors is an integer number (647192).

Almost surely, 2^31897152 is an apocalyptic number.

31897152 is a gapful number since it is divisible by the number (32) 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 31897152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54364128).

31897152 is an abundant number, since it is smaller than the sum of its proper divisors (76831104).

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

31897152 is an equidigital number, since it uses as much as digits as its factorization.

31897152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327 (or 305 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 31897152 is about 5647.7563686831. The cubic root of 31897152 is about 317.1397182200.

The spelling of 31897152 in words is "thirty-one million, eight hundred ninety-seven thousand, one hundred fifty-two".