21120394 has 16 divisors (see below), whose sum is σ = 33685632. Its totient is φ = 9909328.

The previous prime is 21120391. The next prime is 21120403. The reversal of 21120394 is 49302112.

It is not an unprimeable number, because it can be changed into a prime (21120391) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1894 + ... + 6769.

It is an arithmetic number, because the mean of its divisors is an integer number (2105352).

Almost surely, 2^21120394 is an apocalyptic number.

21120394 is a deficient number, since it is larger than the sum of its proper divisors (12565238).

21120394 is a wasteful number, since it uses less digits than its factorization.

21120394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8741.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 21120394 is about 4595.6929836533. The cubic root of 21120394 is about 276.4186480703.

The spelling of 21120394 in words is "twenty-one million, one hundred twenty thousand, three hundred ninety-four".