31661487 has 48 divisors (see below), whose sum is σ = 54626208. Its totient is φ = 17418240.

The previous prime is 31661477. The next prime is 31661491. The reversal of 31661487 is 78416613.

31661487 is a `hidden beast` number, since 31 + 6 + 614 + 8 + 7 = 666.

It is not a de Polignac number, because 31661487 - 2⁶ = 31661423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31661437) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 93783 + ... + 94119.

It is an arithmetic number, because the mean of its divisors is an integer number (1138046).

Almost surely, 2^31661487 is an apocalyptic number.

31661487 is a deficient number, since it is larger than the sum of its proper divisors (22964721).

31661487 is a wasteful number, since it uses less digits than its factorization.

31661487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440 (or 437 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 31661487 is about 5626.8540944297. The cubic root of 31661487 is about 316.3567480619.

The spelling of 31661487 in words is "thirty-one million, six hundred sixty-one thousand, four hundred eighty-seven".