77191581000 has 128 divisors (see below), whose sum is σ = 248606991360. Its totient is φ = 19920384000.

The previous prime is 77191580959. The next prime is 77191581001. The reversal of 77191581000 is 18519177.

It is a super-2 number, since 2×77191581000² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 77191581000.

It is not an unprimeable number, because it can be changed into a prime (77191581001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 322009 + ... + 508008.

It is an arithmetic number, because the mean of its divisors is an integer number (1942242120).

Almost surely, 2^77191581000 is an apocalyptic number.

It is an amenable number.

77191581000 is an abundant number, since it is smaller than the sum of its proper divisors (171415410360).

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

77191581000 is a wasteful number, since it uses less digits than its factorization.

77191581000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 830072 (or 830058 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 39.

The spelling of 77191581000 in words is "seventy-seven billion, one hundred ninety-one million, five hundred eighty-one thousand".