77691 has 16 divisors (see below), whose sum is σ = 115200. Its totient is φ = 46368.

The previous prime is 77689. The next prime is 77699. The reversal of 77691 is 19677.

77691 = T₄₄ + T₄₅ + ... + T₈₁.

It is not a de Polignac number, because 77691 - 2¹ = 77689 is a prime.

It is a super-3 number, since 3×77691³ = 1406803335151113, which contains 333 as substring.

Its product of digits (2646) is a multiple of the sum of its prime divisors (98).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 77691.

It is not an unprimeable number, because it can be changed into a prime (77699) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1630 + ... + 1676.

It is an arithmetic number, because the mean of its divisors is an integer number (7200).

2⁷⁷⁶⁹¹ is an apocalyptic number.

77691 is a deficient number, since it is larger than the sum of its proper divisors (37509).

77691 is a wasteful number, since it uses less digits than its factorization.

77691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98.

The product of its digits is 2646, while the sum is 30.

The square root of 77691 is about 278.7310531677. The cubic root of 77691 is about 42.6700911422.

The spelling of 77691 in words is "seventy-seven thousand, six hundred ninety-one".