77646653187840 has 1440 divisors, whose sum is σ = 321464331308736. Its totient is φ = 17686155755520.

The previous prime is 77646653187799. The next prime is 77646653187893. The reversal of 77646653187840 is 4878135664677.

77646653187840 is a `hidden beast` number, since 7 + 7 + 6 + 4 + 6 + 6 + 531 + 8 + 7 + 84 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1440).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

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, 12660465414 + ... + 12660471546.

Almost surely, 2^{77646653187840} 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 77646653187840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160732165654368).

77646653187840 is an abundant number, since it is smaller than the sum of its proper divisors (243817678120896).

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

77646653187840 is a wasteful number, since it uses less digits than its factorization.

77646653187840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6847 (or 6824 counting only the distinct ones).

The product of its (nonzero) digits is 1137991680, while the sum is 72.

The spelling of 77646653187840 in words is "seventy-seven trillion, six hundred forty-six billion, six hundred fifty-three million, one hundred eighty-seven thousand, eight hundred forty".