31980526561 has 3 divisors (see below), whose sum is σ = 31980705393. Its totient is φ = 31980347730.

The previous prime is 31980526537. The next prime is 31980526573. The reversal of 31980526561 is 16562508913.

The square root of 31980526561 is 178831.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16562508913 = 29 ⋅571120997.

It is a de Polignac number, because none of the positive numbers 2^k-31980526561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31980526511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 89416 + ... + 268246.

It is an arithmetic number, because the mean of its divisors is an integer number (10660235131).

Almost surely, 2^31980526561 is an apocalyptic number.

31980526561 is the 178831-st square number.

31980526561 is the 89416-th centered octagonal number.

It is an amenable number.

31980526561 is a deficient number, since it is larger than the sum of its proper divisors (178832).

31980526561 is an frugal number, since it uses more digits than its factorization.

31980526561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357662 (or 178831 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 46.

The spelling of 31980526561 in words is "thirty-one billion, nine hundred eighty million, five hundred twenty-six thousand, five hundred sixty-one".