21293642 has 16 divisors (see below), whose sum is σ = 33942240. Its totient is φ = 9990288.

The previous prime is 21293633. The next prime is 21293647. The reversal of 21293642 is 24639212.

It is not an unprimeable number, because it can be changed into a prime (21293647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1448 + ... + 6684.

It is an arithmetic number, because the mean of its divisors is an integer number (2121390).

Almost surely, 2^21293642 is an apocalyptic number.

21293642 is a deficient number, since it is larger than the sum of its proper divisors (12648598).

21293642 is a wasteful number, since it uses less digits than its factorization.

21293642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5365.

The product of its digits is 5184, while the sum is 29.

The square root of 21293642 is about 4614.5034402414. The cubic root of 21293642 is about 277.1724002486.

The spelling of 21293642 in words is "twenty-one million, two hundred ninety-three thousand, six hundred forty-two".