77844541688 has 16 divisors (see below), whose sum is σ = 150666855360. Its totient is φ = 37666713600.

The previous prime is 77844541633. The next prime is 77844541703. The reversal of 77844541688 is 88614544877.

It is a super-2 number, since 2×77844541688² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (62).

It is a self number, because there is not a number n which added to its sum of digits gives 77844541688.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156944393 + ... + 156944888.

It is an arithmetic number, because the mean of its divisors is an integer number (9416678460).

Almost surely, 2^77844541688 is an apocalyptic number.

It is an amenable number.

77844541688 is a deficient number, since it is larger than the sum of its proper divisors (72822313672).

77844541688 is a wasteful number, since it uses less digits than its factorization.

77844541688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 313889318 (or 313889314 counting only the distinct ones).

The product of its digits is 48168960, while the sum is 62.

The spelling of 77844541688 in words is "seventy-seven billion, eight hundred forty-four million, five hundred forty-one thousand, six hundred eighty-eight".