679431726947781 has 40 divisors (see below), whose sum is σ = 1068375592495200. Its totient is φ = 429113402762400.

The previous prime is 679431726947767. The next prime is 679431726947803. The reversal of 679431726947781 is 187749627134976.

679431726947781 is a `hidden beast` number, since 6 + 7 + 9 + 4 + 3 + 1 + 7 + 2 + 69 + 477 + 81 = 666.

It is not a de Polignac number, because 679431726947781 - 2⁷ = 679431726947653 is a prime.

It is a super-2 number, since 2×679431726947781² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a self number, because there is not a number n which added to its sum of digits gives 679431726947781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (679431726947741) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 719242875 + ... + 720186903.

It is an arithmetic number, because the mean of its divisors is an integer number (26709389812380).

Almost surely, 2^{679431726947781} is an apocalyptic number.

It is an amenable number.

679431726947781 is a deficient number, since it is larger than the sum of its proper divisors (388943865547419).

679431726947781 is a wasteful number, since it uses less digits than its factorization.

679431726947781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1411711 (or 1411702 counting only the distinct ones).

The product of its digits is 5377010688, while the sum is 81.

The spelling of 679431726947781 in words is "six hundred seventy-nine trillion, four hundred thirty-one billion, seven hundred twenty-six million, nine hundred forty-seven thousand, seven hundred eighty-one".