90188913981 has 8 divisors (see below), whose sum is σ = 120256374784. Its totient is φ = 60123697920.

The previous prime is 90188913973. The next prime is 90188914099. The reversal of 90188913981 is 18931988109.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 90188913981 - 2³ = 90188913973 is a prime.

It is a super-2 number, since 2×90188913981² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90188915981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 465085 + ... + 629826.

It is an arithmetic number, because the mean of its divisors is an integer number (15032046848).

Almost surely, 2^90188913981 is an apocalyptic number.

It is an amenable number.

90188913981 is a deficient number, since it is larger than the sum of its proper divisors (30067460803).

90188913981 is a wasteful number, since it uses less digits than its factorization.

90188913981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1122371.

The product of its (nonzero) digits is 1119744, while the sum is 57.

The spelling of 90188913981 in words is "ninety billion, one hundred eighty-eight million, nine hundred thirteen thousand, nine hundred eighty-one".