31406728 has 8 divisors (see below), whose sum is σ = 58887630. Its totient is φ = 15703360.

The previous prime is 31406699. The next prime is 31406731. The reversal of 31406728 is 82760413.

It can be written as a sum of positive squares in only one way, i.e., 31158724 + 248004 = 5582^2 + 498^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 31406728.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1962913 + ... + 1962928.

Almost surely, 2^31406728 is an apocalyptic number.

It is an amenable number.

31406728 is a deficient number, since it is larger than the sum of its proper divisors (27480902).

31406728 is a wasteful number, since it uses less digits than its factorization.

31406728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3925847 (or 3925843 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 31406728 is about 5604.1705898375. The cubic root of 31406728 is about 315.5059576952.

The spelling of 31406728 in words is "thirty-one million, four hundred six thousand, seven hundred twenty-eight".