90909099181 has 4 divisors (see below), whose sum is σ = 91014440832. Its totient is φ = 90803757532.

The previous prime is 90909099131. The next prime is 90909099199. The reversal of 90909099181 is 18199090909.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18199090909 = 103 ⋅176690203.

It is a cyclic number.

It is not a de Polignac number, because 90909099181 - 2²¹ = 90907002029 is a prime.

It is a super-2 number, since 2×90909099181² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90909099101) 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, 52669531 + ... + 52671256.

It is an arithmetic number, because the mean of its divisors is an integer number (22753610208).

Almost surely, 2^90909099181 is an apocalyptic number.

It is an amenable number.

90909099181 is a deficient number, since it is larger than the sum of its proper divisors (105341651).

90909099181 is a wasteful number, since it uses less digits than its factorization.

90909099181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105341650.

The product of its (nonzero) digits is 472392, while the sum is 55.

The spelling of 90909099181 in words is "ninety billion, nine hundred nine million, ninety-nine thousand, one hundred eighty-one".