813668251 has 16 divisors (see below), whose sum is σ = 897724800. Its totient is φ = 737427240.

The previous prime is 813668239. The next prime is 813668257. The reversal of 813668251 is 152866318.

It is not a de Polignac number, because 813668251 - 2⁷ = 813668123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (813668257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 556960 + ... + 558418.

It is an arithmetic number, because the mean of its divisors is an integer number (56107800).

Almost surely, 2^813668251 is an apocalyptic number.

813668251 is a deficient number, since it is larger than the sum of its proper divisors (84056549).

813668251 is a wasteful number, since it uses less digits than its factorization.

813668251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1911 (or 1889 counting only the distinct ones).

The product of its digits is 69120, while the sum is 40.

The square root of 813668251 is about 28524.8707446677. The cubic root of 813668251 is about 933.5748068088.

The spelling of 813668251 in words is "eight hundred thirteen million, six hundred sixty-eight thousand, two hundred fifty-one".