90127981 has 4 divisors (see below), whose sum is σ = 90150592. Its totient is φ = 90105372.

The previous prime is 90127979. The next prime is 90128021. The reversal of 90127981 is 18972109.

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 90127981 - 2¹ = 90127979 is a prime.

It is a super-2 number, since 2×90127981² = 16246105918272722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 90127981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90127951) 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, 3555 + ... + 13888.

It is an arithmetic number, because the mean of its divisors is an integer number (22537648).

Almost surely, 2^90127981 is an apocalyptic number.

It is an amenable number.

90127981 is a deficient number, since it is larger than the sum of its proper divisors (22611).

90127981 is a wasteful number, since it uses less digits than its factorization.

90127981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22610.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 90127981 is about 9493.5757752282. The cubic root of 90127981 is about 448.3527942920.

It can be divided in two parts, 901 and 27981, that added together give a palindrome (28882).

The spelling of 90127981 in words is "ninety million, one hundred twenty-seven thousand, nine hundred eighty-one".