77531644 has 6 divisors (see below), whose sum is σ = 135680384. Its totient is φ = 38765820.

The previous prime is 77531639. The next prime is 77531659. The reversal of 77531644 is 44613577.

It is a super-2 number, since 2×77531644² = 12022311642685472, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9691452 + ... + 9691459.

Almost surely, 2^77531644 is an apocalyptic number.

It is an amenable number.

77531644 is a deficient number, since it is larger than the sum of its proper divisors (58148740).

77531644 is a wasteful number, since it uses less digits than its factorization.

77531644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19382915 (or 19382913 counting only the distinct ones).

The product of its digits is 70560, while the sum is 37.

The square root of 77531644 is about 8805.2055058357. The cubic root of 77531644 is about 426.4089690076.

The spelling of 77531644 in words is "seventy-seven million, five hundred thirty-one thousand, six hundred forty-four".