31429520 has 40 divisors (see below), whose sum is σ = 73656000. Its totient is φ = 12471680.

The previous prime is 31429507. The next prime is 31429561. The reversal of 31429520 is 2592413.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 31429520.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8981 + ... + 11979.

It is an arithmetic number, because the mean of its divisors is an integer number (1841400).

Almost surely, 2^31429520 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 31429520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36828000).

31429520 is an abundant number, since it is smaller than the sum of its proper divisors (42226480).

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

31429520 is a wasteful number, since it uses less digits than its factorization.

31429520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3143 (or 3137 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 31429520 is about 5606.2037066093. The cubic root of 31429520 is about 315.5822605919.

The spelling of 31429520 in words is "thirty-one million, four hundred twenty-nine thousand, five hundred twenty".