21859930 has 16 divisors (see below), whose sum is σ = 39592224. Its totient is φ = 8689680.

The previous prime is 21859927. The next prime is 21859949. The reversal of 21859930 is 3995812.

It is a self number, because there is not a number n which added to its sum of digits gives 21859930.

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 7 ways as a sum of consecutive naturals, for example, 5076 + ... + 8335.

It is an arithmetic number, because the mean of its divisors is an integer number (2474514).

Almost surely, 2^21859930 is an apocalyptic number.

21859930 is a deficient number, since it is larger than the sum of its proper divisors (17732294).

21859930 is a wasteful number, since it uses less digits than its factorization.

21859930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13581.

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 21859930 is about 4675.4604051366. The cubic root of 21859930 is about 279.6079973671.

The spelling of 21859930 in words is "twenty-one million, eight hundred fifty-nine thousand, nine hundred thirty".