20660638 has 32 divisors (see below), whose sum is σ = 34020000. Its totient is φ = 9377280.

The previous prime is 20660621. The next prime is 20660659. The reversal of 20660638 is 83606602.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 138588 + ... + 138736.

It is an arithmetic number, because the mean of its divisors is an integer number (1063125).

Almost surely, 2^20660638 is an apocalyptic number.

20660638 is a deficient number, since it is larger than the sum of its proper divisors (13359362).

20660638 is a wasteful number, since it uses less digits than its factorization.

20660638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 20660638 is about 4545.3974523687. The cubic root of 20660638 is about 274.3981902971.

The spelling of 20660638 in words is "twenty million, six hundred sixty thousand, six hundred thirty-eight".