31429872 has 120 divisors (see below), whose sum is σ = 95926896. Its totient is φ = 9566208.

The previous prime is 31429847. The next prime is 31429873. The reversal of 31429872 is 27892413.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31429873) 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, 90403 + ... + 90749.

Almost surely, 2^31429872 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 31429872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47963448).

31429872 is an abundant number, since it is smaller than the sum of its proper divisors (64497024).

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

31429872 is a wasteful number, since it uses less digits than its factorization.

31429872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415 (or 406 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 31429872 is about 5606.2351003146. The cubic root of 31429872 is about 315.5834387258.

The spelling of 31429872 in words is "thirty-one million, four hundred twenty-nine thousand, eight hundred seventy-two".