681562723 has 2 divisors, whose sum is σ = 681562724. Its totient is φ = 681562722.

The previous prime is 681562697. The next prime is 681562729. The reversal of 681562723 is 327265186.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681562723 is a prime.

It is not a weakly prime, because it can be changed into another prime (681562729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340781361 + 340781362.

It is an arithmetic number, because the mean of its divisors is an integer number (340781362).

Almost surely, 2^681562723 is an apocalyptic number.

681562723 is a deficient number, since it is larger than the sum of its proper divisors (1).

681562723 is an equidigital number, since it uses as much as digits as its factorization.

681562723 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 40.

The square root of 681562723 is about 26106.7562711264. The cubic root of 681562723 is about 880.0390491453.

The spelling of 681562723 in words is "six hundred eighty-one million, five hundred sixty-two thousand, seven hundred twenty-three".