91818181901 has 4 divisors (see below), whose sum is σ = 92279580000. Its totient is φ = 91356783804.

The previous prime is 91818181883. The next prime is 91818181909. The reversal of 91818181901 is 10918181819.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 91818181901 - 2¹⁸ = 91817919757 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 (91818181909) 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, 230698751 + ... + 230699148.

It is an arithmetic number, because the mean of its divisors is an integer number (23069895000).

Almost surely, 2^91818181901 is an apocalyptic number.

It is an amenable number.

91818181901 is a deficient number, since it is larger than the sum of its proper divisors (461398099).

91818181901 is a wasteful number, since it uses less digits than its factorization.

91818181901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 461398098.

The product of its (nonzero) digits is 41472, while the sum is 47.

The spelling of 91818181901 in words is "ninety-one billion, eight hundred eighteen million, one hundred eighty-one thousand, nine hundred one".