813761640765 has 12 divisors (see below), whose sum is σ = 1410520177404. Its totient is φ = 434006208384.

The previous prime is 813761640751. The next prime is 813761640863. The reversal of 813761640765 is 567046167318.

813761640765 is a `hidden beast` number, since 8 + 13 + 7 + 616 + 4 + 0 + 7 + 6 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 174532608441 + 639229032324 = 417771^2 + 799518^2 .

It is not a de Polignac number, because 813761640765 - 2⁶ = 813761640701 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9041795964 + ... + 9041796053.

It is an arithmetic number, because the mean of its divisors is an integer number (117543348117).

Almost surely, 2^813761640765 is an apocalyptic number.

It is an amenable number.

813761640765 is a deficient number, since it is larger than the sum of its proper divisors (596758536639).

813761640765 is a wasteful number, since it uses less digits than its factorization.

813761640765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18083592028 (or 18083592025 counting only the distinct ones).

The product of its (nonzero) digits is 5080320, while the sum is 54.

The spelling of 813761640765 in words is "eight hundred thirteen billion, seven hundred sixty-one million, six hundred forty thousand, seven hundred sixty-five".