91557951427 has 4 divisors (see below), whose sum is σ = 91622933640. Its totient is φ = 91492969216.

The previous prime is 91557951421. The next prime is 91557951439. The reversal of 91557951427 is 72415975519.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 72415975519 = 7901 ⋅9165419.

It is a cyclic number.

It is not a de Polignac number, because 91557951427 - 2²⁷ = 91423733699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91557951421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32488993 + ... + 32491810.

It is an arithmetic number, because the mean of its divisors is an integer number (22905733410).

Almost surely, 2^91557951427 is an apocalyptic number.

91557951427 is a deficient number, since it is larger than the sum of its proper divisors (64982213).

91557951427 is a wasteful number, since it uses less digits than its factorization.

91557951427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64982212.

The product of its digits is 3969000, while the sum is 55.

The spelling of 91557951427 in words is "ninety-one billion, five hundred fifty-seven million, nine hundred fifty-one thousand, four hundred twenty-seven".