681764457431 has 2 divisors, whose sum is σ = 681764457432. Its totient is φ = 681764457430.

The previous prime is 681764457427. The next prime is 681764457449. The reversal of 681764457431 is 134754467186.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 681764457431 - 2² = 681764457427 is a prime.

It is a super-2 number, since 2×681764457431² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681764457461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340882228715 + 340882228716.

It is an arithmetic number, because the mean of its divisors is an integer number (340882228716).

Almost surely, 2^681764457431 is an apocalyptic number.

681764457431 is a deficient number, since it is larger than the sum of its proper divisors (1).

681764457431 is an equidigital number, since it uses as much as digits as its factorization.

681764457431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13547520, while the sum is 56.

The spelling of 681764457431 in words is "six hundred eighty-one billion, seven hundred sixty-four million, four hundred fifty-seven thousand, four hundred thirty-one".