77351865520 has 40 divisors (see below), whose sum is σ = 184703718384. Its totient is φ = 30104508672.

The previous prime is 77351865511. The next prime is 77351865541. The reversal of 77351865520 is 2556815377.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×77351865520² (a number of 23 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (49) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13063234 + ... + 13069153.

Almost surely, 2^77351865520 is an apocalyptic number.

It is an amenable number.

77351865520 is an abundant number, since it is smaller than the sum of its proper divisors (107351852864).

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

77351865520 is a wasteful number, since it uses less digits than its factorization.

77351865520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26132437 (or 26132431 counting only the distinct ones).

The product of its (nonzero) digits is 1764000, while the sum is 49.

The spelling of 77351865520 in words is "seventy-seven billion, three hundred fifty-one million, eight hundred sixty-five thousand, five hundred twenty".