431072561 has 2 divisors, whose sum is σ = 431072562. Its totient is φ = 431072560.

The previous prime is 431072557. The next prime is 431072563. The reversal of 431072561 is 165270134.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 429276961 + 1795600 = 20719^2 + 1340^2 .

It is a cyclic number.

It is not a de Polignac number, because 431072561 - 2² = 431072557 is a prime.

Together with 431072563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (431072563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 215536280 + 215536281.

It is an arithmetic number, because the mean of its divisors is an integer number (215536281).

Almost surely, 2^431072561 is an apocalyptic number.

It is an amenable number.

431072561 is a deficient number, since it is larger than the sum of its proper divisors (1).

431072561 is an equidigital number, since it uses as much as digits as its factorization.

431072561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 431072561 is about 20762.2869886725. The cubic root of 431072561 is about 755.4112701614.

The spelling of 431072561 in words is "four hundred thirty-one million, seventy-two thousand, five hundred sixty-one".