77721906563136 has 1120 divisors, whose sum is σ = 266963470583040. Its totient is φ = 22127866675200.

The previous prime is 77721906563089. The next prime is 77721906563177. The reversal of 77721906563136 is 63136560912777.

77721906563136 is a `hidden beast` number, since 7 + 7 + 72 + 190 + 65 + 6 + 313 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 18326313976 + ... + 18326318216.

It is an arithmetic number, because the mean of its divisors is an integer number (238360241592).

Almost surely, 2^{77721906563136} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77721906563136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133481735291520).

77721906563136 is an abundant number, since it is smaller than the sum of its proper divisors (189241564019904).

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

77721906563136 is a wasteful number, since it uses less digits than its factorization.

77721906563136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4545 (or 4526 counting only the distinct ones).

The product of its (nonzero) digits is 60011280, while the sum is 63.

The spelling of 77721906563136 in words is "seventy-seven trillion, seven hundred twenty-one billion, nine hundred six million, five hundred sixty-three thousand, one hundred thirty-six".