91899640144901 has 4 divisors (see below), whose sum is σ = 91906245466092. Its totient is φ = 91893034823712.

The previous prime is 91899640144811. The next prime is 91899640144903. The reversal of 91899640144901 is 10944104699819.

It is a Cunningham number, because it is equal to 9586430²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 59288059615876 + 32611580529025 = 7699874^2 + 5710655^2 .

It is a cyclic number.

It is not a de Polignac number, because 91899640144901 - 2²² = 91899635950597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91899640144903) 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, 3302639726 + ... + 3302667551.

It is an arithmetic number, because the mean of its divisors is an integer number (22976561366523).

Almost surely, 2^{91899640144901} is an apocalyptic number.

It is an amenable number.

91899640144901 is a deficient number, since it is larger than the sum of its proper divisors (6605321191).

91899640144901 is a wasteful number, since it uses less digits than its factorization.

91899640144901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6605321190.

The product of its (nonzero) digits is 20155392, while the sum is 65.

The spelling of 91899640144901 in words is "ninety-one trillion, eight hundred ninety-nine billion, six hundred forty million, one hundred forty-four thousand, nine hundred one".