21274442 has 16 divisors (see below), whose sum is σ = 36706560. Its totient is φ = 9058608.

The previous prime is 21274441. The next prime is 21274453. The reversal of 21274442 is 24447212.

It is a super-2 number, since 2×21274442² = 905203764822728, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21274441) 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, 2642 + ... + 7037.

It is an arithmetic number, because the mean of its divisors is an integer number (2294160).

Almost surely, 2^21274442 is an apocalyptic number.

21274442 is a deficient number, since it is larger than the sum of its proper divisors (15432118).

21274442 is a wasteful number, since it uses less digits than its factorization.

21274442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9845.

The product of its digits is 3584, while the sum is 26.

The square root of 21274442 is about 4612.4225738759. The cubic root of 21274442 is about 277.0890684826.

Adding to 21274442 its product of digits (3584), we get a triangular number (21278026 = T₆₅₂₃).

The spelling of 21274442 in words is "twenty-one million, two hundred seventy-four thousand, four hundred forty-two".