77666631 has 16 divisors (see below), whose sum is σ = 118637568. Its totient is φ = 44272800.

The previous prime is 77666627. The next prime is 77666647. The reversal of 77666631 is 13666677.

It is not a de Polignac number, because 77666631 - 2² = 77666627 is a prime.

It is a super-2 number, since 2×77666631² = 12064211141780322, which contains 22 as substring.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77666621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4761 + ... + 13341.

It is an arithmetic number, because the mean of its divisors is an integer number (7414848).

Almost surely, 2^77666631 is an apocalyptic number.

77666631 is a deficient number, since it is larger than the sum of its proper divisors (40970937).

77666631 is a wasteful number, since it uses less digits than its factorization.

77666631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9022.

The product of its digits is 190512, while the sum is 42.

The square root of 77666631 is about 8812.8673540454. The cubic root of 77666631 is about 426.6562929471.

The spelling of 77666631 in words is "seventy-seven million, six hundred sixty-six thousand, six hundred thirty-one".