77865816091 has 16 divisors (see below), whose sum is σ = 95138993664. Its totient is φ = 62206245504.

The previous prime is 77865816071. The next prime is 77865816121. The reversal of 77865816091 is 19061856877.

It is not a de Polignac number, because 77865816091 - 2⁹ = 77865815579 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77865816011) 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, 3164125 + ... + 3188638.

It is an arithmetic number, because the mean of its divisors is an integer number (5946187104).

Almost surely, 2^77865816091 is an apocalyptic number.

77865816091 is a deficient number, since it is larger than the sum of its proper divisors (17273177573).

77865816091 is a wasteful number, since it uses less digits than its factorization.

77865816091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6352890.

The product of its (nonzero) digits is 5080320, while the sum is 58.

The spelling of 77865816091 in words is "seventy-seven billion, eight hundred sixty-five million, eight hundred sixteen thousand, ninety-one".