90639879 has 8 divisors (see below), whose sum is σ = 131839872. Its totient is φ = 54933240.

The previous prime is 90639851. The next prime is 90639881. The reversal of 90639879 is 97893609.

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

It is not a de Polignac number, because 90639879 - 2⁵ = 90639847 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90639179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1373299 + ... + 1373364.

It is an arithmetic number, because the mean of its divisors is an integer number (16479984).

Almost surely, 2^90639879 is an apocalyptic number.

90639879 is a deficient number, since it is larger than the sum of its proper divisors (41199993).

90639879 is a wasteful number, since it uses less digits than its factorization.

90639879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2746677.

The product of its (nonzero) digits is 734832, while the sum is 51.

The square root of 90639879 is about 9520.4978336219. The cubic root of 90639879 is about 449.2000256252.

The spelling of 90639879 in words is "ninety million, six hundred thirty-nine thousand, eight hundred seventy-nine".