31457920 has 128 divisors (see below), whose sum is σ = 85680000. Its totient is φ = 10948608.

The previous prime is 31457911. The next prime is 31457929. The reversal of 31457920 is 2975413.

It is an interprime number because it is at equal distance from previous prime (31457911) and next prime (31457929).

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31457929) 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, 157981 + ... + 158179.

It is an arithmetic number, because the mean of its divisors is an integer number (669375).

Almost surely, 2^31457920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31457920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42840000).

31457920 is an abundant number, since it is smaller than the sum of its proper divisors (54222080).

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

31457920 is a wasteful number, since it uses less digits than its factorization.

31457920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 250 (or 238 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 31457920 is about 5608.7360429958. The cubic root of 31457920 is about 315.6772863089.

The spelling of 31457920 in words is "thirty-one million, four hundred fifty-seven thousand, nine hundred twenty".