764678531217 has 4 divisors (see below), whose sum is σ = 1019571374960. Its totient is φ = 509785687476.

The previous prime is 764678531191. The next prime is 764678531261. The reversal of 764678531217 is 712135876467.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 764678531217 - 2⁸ = 764678530961 is a prime.

It is a super-2 number, since 2×764678531217² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (764678535217) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127446421867 + ... + 127446421872.

It is an arithmetic number, because the mean of its divisors is an integer number (254892843740).

Almost surely, 2^764678531217 is an apocalyptic number.

It is an amenable number.

764678531217 is a deficient number, since it is larger than the sum of its proper divisors (254892843743).

764678531217 is a wasteful number, since it uses less digits than its factorization.

764678531217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254892843742.

The product of its digits is 11854080, while the sum is 57.

The spelling of 764678531217 in words is "seven hundred sixty-four billion, six hundred seventy-eight million, five hundred thirty-one thousand, two hundred seventeen".