77044644 has 18 divisors (see below), whose sum is σ = 194751830. Its totient is φ = 25681536.

The previous prime is 77044633. The next prime is 77044657. The reversal of 77044644 is 44644077.

77044644 is a `hidden beast` number, since 7 + 7 + 0 + 4 + 4 + 644 = 666.

It can be written as a sum of positive squares in only one way, i.e., 76212900 + 831744 = 8730^2 + 912^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 2140129 = 77044644 / (7 + 7 + 0 + 4 + 4 + 6 + 4 + 4).

It is a junction number, because it is equal to n+sod(n) for n = 77044599 and 77044608.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1070029 + ... + 1070100.

Almost surely, 2^77044644 is an apocalyptic number.

It is an amenable number.

77044644 is an abundant number, since it is smaller than the sum of its proper divisors (117707186).

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

77044644 is a wasteful number, since it uses less digits than its factorization.

77044644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2140139 (or 2140134 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 36.

The square root of 77044644 is about 8777.5078467638. The cubic root of 77044644 is about 425.5142913625.

The spelling of 77044644 in words is "seventy-seven million, forty-four thousand, six hundred forty-four".