31216928 has 48 divisors (see below), whose sum is σ = 63345240. Its totient is φ = 15138816.

The previous prime is 31216921. The next prime is 31216951. The reversal of 31216928 is 82961213.

It can be written as a sum of positive squares in 4 ways, for example, as 11751184 + 19465744 = 3428^2 + 4412^2 .

It is a super-4 number, since 4×31216928⁴ (a number of 31 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 31216894 and 31216903.

It is not an unprimeable number, because it can be changed into a prime (31216921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 276200 + ... + 276312.

Almost surely, 2^31216928 is an apocalyptic number.

It is an amenable number.

31216928 is an abundant number, since it is smaller than the sum of its proper divisors (32128312).

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

31216928 is a wasteful number, since it uses less digits than its factorization.

31216928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309 (or 301 counting only the distinct ones).

The product of its digits is 5184, while the sum is 32.

The square root of 31216928 is about 5587.2111111001. The cubic root of 31216928 is about 314.8691082956.

The spelling of 31216928 in words is "thirty-one million, two hundred sixteen thousand, nine hundred twenty-eight".