31400928 has 72 divisors (see below), whose sum is σ = 96176808. Its totient is φ = 9660672.

The previous prime is 31400893. The next prime is 31400933. The reversal of 31400928 is 82900413.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×31400928² = 1972036558522368, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 450 + ... + 7937.

It is an arithmetic number, because the mean of its divisors is an integer number (1335789).

Almost surely, 2^31400928 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 31400928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48088404).

31400928 is an abundant number, since it is smaller than the sum of its proper divisors (64775880).

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

31400928 is a wasteful number, since it uses less digits than its factorization.

31400928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8416 (or 8405 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 31400928 is about 5603.6530941878. The cubic root of 31400928 is about 315.4865346041.

The spelling of 31400928 in words is "thirty-one million, four hundred thousand, nine hundred twenty-eight".