21790659 has 16 divisors (see below), whose sum is σ = 31912704. Its totient is φ = 13116000.

The previous prime is 21790633. The next prime is 21790673. The reversal of 21790659 is 95609712.

It is not a de Polignac number, because 21790659 - 2⁸ = 21790403 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21790609) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2797 + ... + 7169.

It is an arithmetic number, because the mean of its divisors is an integer number (1994544).

Almost surely, 2^21790659 is an apocalyptic number.

21790659 is a deficient number, since it is larger than the sum of its proper divisors (10122045).

21790659 is a wasteful number, since it uses less digits than its factorization.

21790659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4538.

The product of its (nonzero) digits is 34020, while the sum is 39.

The square root of 21790659 is about 4668.0465935978. The cubic root of 21790659 is about 279.3123388938.

The spelling of 21790659 in words is "twenty-one million, seven hundred ninety thousand, six hundred fifty-nine".