77911680 has 512 divisors, whose sum is σ = 338411520. Its totient is φ = 14745600.

The previous prime is 77911651. The next prime is 77911699. The reversal of 77911680 is 8611977.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2513265 + ... + 2513295.

It is an arithmetic number, because the mean of its divisors is an integer number (660960).

Almost surely, 2^77911680 is an apocalyptic number.

77911680 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 77911680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169205760).

77911680 is an abundant number, since it is smaller than the sum of its proper divisors (260499840).

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

77911680 is a wasteful number, since it uses less digits than its factorization.

77911680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88 (or 76 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 39.

The square root of 77911680 is about 8826.7593147202. The cubic root of 77911680 is about 427.1045417877.

The spelling of 77911680 in words is "seventy-seven million, nine hundred eleven thousand, six hundred eighty".