90139870 has 16 divisors (see below), whose sum is σ = 162629280. Its totient is φ = 35972064.

The previous prime is 90139849. The next prime is 90139871. The reversal of 90139870 is 7893109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90139871) 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, 5877 + ... + 14656.

It is an arithmetic number, because the mean of its divisors is an integer number (10164330).

Almost surely, 2^90139870 is an apocalyptic number.

90139870 is a deficient number, since it is larger than the sum of its proper divisors (72489410).

90139870 is a wasteful number, since it uses less digits than its factorization.

90139870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20979.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 90139870 is about 9494.2019148531. The cubic root of 90139870 is about 448.3725078591.

Subtracting from 90139870 its reverse (7893109), we obtain a square (82246761 = 9069²).

The spelling of 90139870 in words is "ninety million, one hundred thirty-nine thousand, eight hundred seventy".