681732497 has 2 divisors, whose sum is σ = 681732498. Its totient is φ = 681732496.

The previous prime is 681732431. The next prime is 681732517. The reversal of 681732497 is 794237186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 597753601 + 83978896 = 24449^2 + 9164^2 .

It is a cyclic number.

It is not a de Polignac number, because 681732497 - 2¹⁶ = 681666961 is a prime.

It is not a weakly prime, because it can be changed into another prime (681732427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340866248 + 340866249.

It is an arithmetic number, because the mean of its divisors is an integer number (340866249).

Almost surely, 2^681732497 is an apocalyptic number.

It is an amenable number.

681732497 is a deficient number, since it is larger than the sum of its proper divisors (1).

681732497 is an equidigital number, since it uses as much as digits as its factorization.

681732497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 47.

The square root of 681732497 is about 26110.0076024501. The cubic root of 681732497 is about 880.1121142454.

The spelling of 681732497 in words is "six hundred eighty-one million, seven hundred thirty-two thousand, four hundred ninety-seven".