31728172 has 12 divisors (see below), whose sum is σ = 63456400. Its totient is φ = 13597776.

The previous prime is 31728133. The next prime is 31728181. The reversal of 31728172 is 27182713.

31728172 is an admirable number.

It is a super-3 number, since 3×31728172³ (a number of 23 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 566547 + ... + 566602.

Almost surely, 2^31728172 is an apocalyptic number.

It is an amenable number.

31728172 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

31728172 is a wasteful number, since it uses less digits than its factorization.

31728172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1133160 (or 1133158 counting only the distinct ones).

The product of its digits is 4704, while the sum is 31.

The square root of 31728172 is about 5632.7765799826. The cubic root of 31728172 is about 316.5786944303.

The spelling of 31728172 in words is "thirty-one million, seven hundred twenty-eight thousand, one hundred seventy-two".