21929230 has 32 divisors (see below), whose sum is σ = 41823360. Its totient is φ = 8255520.

The previous prime is 21929209. The next prime is 21929231. The reversal of 21929230 is 3292912.

It is a super-2 number, since 2×21929230² = 961782256785800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21929231) 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 15 ways as a sum of consecutive naturals, for example, 39817 + ... + 40363.

It is an arithmetic number, because the mean of its divisors is an integer number (1306980).

Almost surely, 2^21929230 is an apocalyptic number.

21929230 is a deficient number, since it is larger than the sum of its proper divisors (19894130).

21929230 is a wasteful number, since it uses less digits than its factorization.

21929230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 784.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 21929230 is about 4682.8655756919. The cubic root of 21929230 is about 279.9031552833.

The spelling of 21929230 in words is "twenty-one million, nine hundred twenty-nine thousand, two hundred thirty".