77407157520 has 400 divisors, whose sum is σ = 335187439488. Its totient is φ = 16084500480.

The previous prime is 77407157453. The next prime is 77407157551. The reversal of 77407157520 is 2575170477.

77407157520 is a `hidden beast` number, since 7 + 7 + 4 + 0 + 71 + 57 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 421392 + ... + 576528.

Almost surely, 2^77407157520 is an apocalyptic number.

77407157520 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77407157520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167593719744).

77407157520 is an abundant number, since it is smaller than the sum of its proper divisors (257780281968).

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

77407157520 is a wasteful number, since it uses less digits than its factorization.

77407157520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155180 (or 155165 counting only the distinct ones).

The product of its (nonzero) digits is 480200, while the sum is 45.

The spelling of 77407157520 in words is "seventy-seven billion, four hundred seven million, one hundred fifty-seven thousand, five hundred twenty".