31326561 has 16 divisors (see below), whose sum is σ = 53040000. Its totient is φ = 17900784.

The previous prime is 31326553. The next prime is 31326571. The reversal of 31326561 is 16562313.

31326561 is a `hidden beast` number, since 3 + 1 + 3 + 2 + 656 + 1 = 666.

It is not a de Polignac number, because 31326561 - 2³ = 31326553 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (31326541) 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 15 ways as a sum of consecutive naturals, for example, 82686 + ... + 83063.

It is an arithmetic number, because the mean of its divisors is an integer number (3315000).

Almost surely, 2^31326561 is an apocalyptic number.

It is an amenable number.

31326561 is a deficient number, since it is larger than the sum of its proper divisors (21713439).

31326561 is a wasteful number, since it uses less digits than its factorization.

31326561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165765 (or 165759 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 31326561 is about 5597.0135786864. The cubic root of 31326561 is about 315.2372815344.

Adding to 31326561 its reverse (16562313), we get a palindrome (47888874).

The spelling of 31326561 in words is "thirty-one million, three hundred twenty-six thousand, five hundred sixty-one".