77686944 has 24 divisors (see below), whose sum is σ = 203928480. Its totient is φ = 25895616.

The previous prime is 77686937. The next prime is 77686949. The reversal of 77686944 is 44968677.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×77686944² = 12070522536118272, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (77686949) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 404524 + ... + 404715.

It is an arithmetic number, because the mean of its divisors is an integer number (8497020).

Almost surely, 2^77686944 is an apocalyptic number.

It is an amenable number.

77686944 is an abundant number, since it is smaller than the sum of its proper divisors (126241536).

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

77686944 is a wasteful number, since it uses less digits than its factorization.

77686944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 809252 (or 809244 counting only the distinct ones).

The product of its digits is 2032128, while the sum is 51.

The square root of 77686944 is about 8814.0197412985. The cubic root of 77686944 is about 426.6934857274.

The spelling of 77686944 in words is "seventy-seven million, six hundred eighty-six thousand, nine hundred forty-four".