679745547978 has 64 divisors (see below), whose sum is σ = 1678671993600. Its totient is φ = 182788709376.

The previous prime is 679745547959. The next prime is 679745547983. The reversal of 679745547978 is 879745547976.

It is a super-2 number, since 2×679745547978² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9679551 + ... + 9749522.

It is an arithmetic number, because the mean of its divisors is an integer number (26229249900).

Almost surely, 2^679745547978 is an apocalyptic number.

679745547978 is an abundant number, since it is smaller than the sum of its proper divisors (998926445622).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

679745547978 is a wasteful number, since it uses less digits than its factorization.

679745547978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19429116 (or 19429102 counting only the distinct ones).

The product of its digits is 3734035200, while the sum is 78.

The spelling of 679745547978 in words is "six hundred seventy-nine billion, seven hundred forty-five million, five hundred forty-seven thousand, nine hundred seventy-eight".