681929873 has 2 divisors, whose sum is σ = 681929874. Its totient is φ = 681929872.

The previous prime is 681929863. The next prime is 681929923. The reversal of 681929873 is 378929186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 510398464 + 171531409 = 22592^2 + 13097^2 .

It is a cyclic number.

It is not a de Polignac number, because 681929873 - 2¹⁴ = 681913489 is a prime.

It is a super-2 number, since 2×681929873² = 930056703379592258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (681929803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340964936 + 340964937.

It is an arithmetic number, because the mean of its divisors is an integer number (340964937).

Almost surely, 2^681929873 is an apocalyptic number.

It is an amenable number.

681929873 is a deficient number, since it is larger than the sum of its proper divisors (1).

681929873 is an equidigital number, since it uses as much as digits as its factorization.

681929873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1306368, while the sum is 53.

The square root of 681929873 is about 26113.7870290772. The cubic root of 681929873 is about 880.1970430836.

The spelling of 681929873 in words is "six hundred eighty-one million, nine hundred twenty-nine thousand, eight hundred seventy-three".