77669891 has 8 divisors (see below), whose sum is σ = 88047120. Its totient is φ = 67921632.

The previous prime is 77669831. The next prime is 77669903. The reversal of 77669891 is 19896677.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77669891 - 2²⁶ = 10561027 is a prime.

It is a super-2 number, since 2×77669891² = 12065223935903762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77669831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156980 + ... + 157473.

It is an arithmetic number, because the mean of its divisors is an integer number (11005890).

Almost surely, 2^77669891 is an apocalyptic number.

77669891 is a deficient number, since it is larger than the sum of its proper divisors (10377229).

77669891 is a wasteful number, since it uses less digits than its factorization.

77669891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 314485.

The product of its digits is 1143072, while the sum is 53.

The square root of 77669891 is about 8813.0523089336. The cubic root of 77669891 is about 426.6622623921.

The spelling of 77669891 in words is "seventy-seven million, six hundred sixty-nine thousand, eight hundred ninety-one".