77696640 has 384 divisors, whose sum is σ = 320785920. Its totient is φ = 16957440.

The previous prime is 77696621. The next prime is 77696669. The reversal of 77696640 is 4669677.

It is a tau number, because it is divible by the number of its divisors (384).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1653097 + ... + 1653143.

It is an arithmetic number, because the mean of its divisors is an integer number (835380).

Almost surely, 2^77696640 is an apocalyptic number.

77696640 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 77696640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160392960).

77696640 is an abundant number, since it is smaller than the sum of its proper divisors (243089280).

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

77696640 is a wasteful number, since it uses less digits than its factorization.

77696640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 105 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 45.

The square root of 77696640 is about 8814.5697569422. The cubic root of 77696640 is about 426.7112366635.

The spelling of 77696640 in words is "seventy-seven million, six hundred ninety-six thousand, six hundred forty".