31660072 has 8 divisors (see below), whose sum is σ = 59362650. Its totient is φ = 15830032.

The previous prime is 31660063. The next prime is 31660127. The reversal of 31660072 is 27006613.

It can be written as a sum of positive squares in only one way, i.e., 31292836 + 367236 = 5594^2 + 606^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1978747 + ... + 1978762.

Almost surely, 2^31660072 is an apocalyptic number.

It is an amenable number.

31660072 is a deficient number, since it is larger than the sum of its proper divisors (27702578).

31660072 is a wasteful number, since it uses less digits than its factorization.

31660072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3957515 (or 3957511 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 25.

The square root of 31660072 is about 5626.7283566918. The cubic root of 31660072 is about 316.3520351703.

Adding to 31660072 its reverse (27006613), we get a palindrome (58666685).

The spelling of 31660072 in words is "thirty-one million, six hundred sixty thousand, seventy-two".