31146561 has 12 divisors (see below), whose sum is σ = 45227520. Its totient is φ = 20654520.

The previous prime is 31146559. The next prime is 31146569. The reversal of 31146561 is 16564113.

31146561 is a `hidden beast` number, since 3 + 1 + 1 + 4 + 656 + 1 = 666.

It is not a de Polignac number, because 31146561 - 2¹ = 31146559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (31146569) 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 11 ways as a sum of consecutive naturals, for example, 7341 + ... + 10778.

It is an arithmetic number, because the mean of its divisors is an integer number (3768960).

Almost surely, 2^31146561 is an apocalyptic number.

It is an amenable number.

31146561 is a deficient number, since it is larger than the sum of its proper divisors (14080959).

31146561 is a wasteful number, since it uses less digits than its factorization.

31146561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18316 (or 18313 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 31146561 is about 5580.9104096016. The cubic root of 31146561 is about 314.6323450538.

The spelling of 31146561 in words is "thirty-one million, one hundred forty-six thousand, five hundred sixty-one".