77643816 has 16 divisors (see below), whose sum is σ = 194109600. Its totient is φ = 25881264.

The previous prime is 77643803. The next prime is 77643827. The reversal of 77643816 is 61834677.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1617556 + ... + 1617603.

It is an arithmetic number, because the mean of its divisors is an integer number (12131850).

Almost surely, 2^77643816 is an apocalyptic number.

It is an amenable number.

77643816 is an abundant number, since it is smaller than the sum of its proper divisors (116465784).

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

77643816 is a wasteful number, since it uses less digits than its factorization.

77643816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3235168 (or 3235164 counting only the distinct ones).

The product of its digits is 169344, while the sum is 42.

The square root of 77643816 is about 8811.5728448444. The cubic root of 77643816 is about 426.6145113115.

The spelling of 77643816 in words is "seventy-seven million, six hundred forty-three thousand, eight hundred sixteen".