31465728 has 108 divisors (see below), whose sum is σ = 103737088. Its totient is φ = 8985600.

The previous prime is 31465727. The next prime is 31465741. The reversal of 31465728 is 82756413.

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

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 31465692 and 31465701.

It is not an unprimeable number, because it can be changed into a prime (31465727) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15153 + ... + 17103.

Almost surely, 2^31465728 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 31465728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51868544).

31465728 is an abundant number, since it is smaller than the sum of its proper divisors (72271360).

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

31465728 is a wasteful number, since it uses less digits than its factorization.

31465728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1980 (or 1963 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 31465728 is about 5609.4320568129. The cubic root of 31465728 is about 315.7034016650.

The spelling of 31465728 in words is "thirty-one million, four hundred sixty-five thousand, seven hundred twenty-eight".