681393051 has 24 divisors (see below), whose sum is σ = 1025022336. Its totient is φ = 435697920.

The previous prime is 681393001. The next prime is 681393059. The reversal of 681393051 is 150393186.

It is a happy number.

It is not a de Polignac number, because 681393051 - 2⁷ = 681392923 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 681392997 and 681393015.

It is not an unprimeable number, because it can be changed into a prime (681393059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20721 + ... + 42333.

It is an arithmetic number, because the mean of its divisors is an integer number (42709264).

Almost surely, 2^681393051 is an apocalyptic number.

681393051 is a deficient number, since it is larger than the sum of its proper divisors (343629285).

681393051 is a wasteful number, since it uses less digits than its factorization.

681393051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21763 (or 21760 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 681393051 is about 26103.5064885927. The cubic root of 681393051 is about 879.9660158191.

The spelling of 681393051 in words is "six hundred eighty-one million, three hundred ninety-three thousand, fifty-one".