91678767459409 has 27 divisors (see below), whose sum is σ = 100786434726033. Its totient is φ = 83355888350592.

The previous prime is 91678767459319. The next prime is 91678767459443. The reversal of 91678767459409 is 90495476787619.

The square root of 91678767459409 is 9574903.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 43032327369409 + 48646440090000 = 6559903^2 + 6974700^2 .

It is not a de Polignac number, because 91678767459409 - 2⁷ = 91678767459281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91678767429409) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 8339735017 + ... + 8339746009.

It is an arithmetic number, because the mean of its divisors is an integer number (3732830915779).

Almost surely, 2^{91678767459409} is an apocalyptic number.

91678767459409 is the 9574903-rd square number.

91678767459409 is the 4787452-nd centered octagonal number.

It is an amenable number.

91678767459409 is a deficient number, since it is larger than the sum of its proper divisors (9107667266624).

91678767459409 is an frugal number, since it uses more digits than its factorization.

91678767459409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22146 (or 11073 counting only the distinct ones).

The product of its (nonzero) digits is 5761082880, while the sum is 82.

The spelling of 91678767459409 in words is "ninety-one trillion, six hundred seventy-eight billion, seven hundred sixty-seven million, four hundred fifty-nine thousand, four hundred nine".