77905376640 has 1536 divisors, whose sum is σ = 354086553600. Its totient is φ = 15837659136.

The previous prime is 77905376629. The next prime is 77905376669. The reversal of 77905376640 is 4667350977.

77905376640 is a `hidden beast` number, since 7 + 7 + 9 + 0 + 537 + 66 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 756362829 + ... + 756362931.

It is an arithmetic number, because the mean of its divisors is an integer number (230525100).

Almost surely, 2^77905376640 is an apocalyptic number.

77905376640 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 77905376640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (177043276800).

77905376640 is an abundant number, since it is smaller than the sum of its proper divisors (276181176960).

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

77905376640 is a wasteful number, since it uses less digits than its factorization.

77905376640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201 (or 170 counting only the distinct ones).

The product of its (nonzero) digits is 6667920, while the sum is 54.

The spelling of 77905376640 in words is "seventy-seven billion, nine hundred five million, three hundred seventy-six thousand, six hundred forty".