90644139 has 6 divisors (see below), whose sum is σ = 130930436. Its totient is φ = 60429420.

The previous prime is 90644083. The next prime is 90644149. The reversal of 90644139 is 93144609.

90644139 is a `hidden beast` number, since 9 + 0 + 644 + 1 + 3 + 9 = 666.

It is not a de Polignac number, because 90644139 - 2⁷ = 90644011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90644149) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5035777 + ... + 5035794.

Almost surely, 2^90644139 is an apocalyptic number.

90644139 is a deficient number, since it is larger than the sum of its proper divisors (40286297).

90644139 is a wasteful number, since it uses less digits than its factorization.

90644139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10071577 (or 10071574 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 90644139 is about 9520.7215587895. The cubic root of 90644139 is about 449.2070628592.

It can be divided in two parts, 9064 and 4139, that added together give a triangular number (13203 = T₁₆₂).

The spelling of 90644139 in words is "ninety million, six hundred forty-four thousand, one hundred thirty-nine".