20639590 has 16 divisors (see below), whose sum is σ = 38432880. Its totient is φ = 7971040.

The previous prime is 20639587. The next prime is 20639623. The reversal of 20639590 is 9593602.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35296 + ... + 35875.

It is an arithmetic number, because the mean of its divisors is an integer number (2402055).

Almost surely, 2^20639590 is an apocalyptic number.

20639590 is a deficient number, since it is larger than the sum of its proper divisors (17793290).

20639590 is a wasteful number, since it uses less digits than its factorization.

20639590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71207.

The product of its (nonzero) digits is 14580, while the sum is 34.

The square root of 20639590 is about 4543.0815533072. The cubic root of 20639590 is about 274.3049776949.

The spelling of 20639590 in words is "twenty million, six hundred thirty-nine thousand, five hundred ninety".