31440545561 has 2 divisors, whose sum is σ = 31440545562. Its totient is φ = 31440545560.

The previous prime is 31440545471. The next prime is 31440545579. The reversal of 31440545561 is 16554504413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29024233225 + 2416312336 = 170365^2 + 49156^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31440545561 is a prime.

It is not a weakly prime, because it can be changed into another prime (31440545261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15720272780 + 15720272781.

It is an arithmetic number, because the mean of its divisors is an integer number (15720272781).

Almost surely, 2^31440545561 is an apocalyptic number.

It is an amenable number.

31440545561 is a deficient number, since it is larger than the sum of its proper divisors (1).

31440545561 is an equidigital number, since it uses as much as digits as its factorization.

31440545561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144000, while the sum is 38.

The spelling of 31440545561 in words is "thirty-one billion, four hundred forty million, five hundred forty-five thousand, five hundred sixty-one".