21464439 has 16 divisors (see below), whose sum is σ = 29453952. Its totient is φ = 13896288.

The previous prime is 21464423. The next prime is 21464447. The reversal of 21464439 is 93446412.

It is not a de Polignac number, because 21464439 - 2⁴ = 21464423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21464449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28917 + ... + 29649.

It is an arithmetic number, because the mean of its divisors is an integer number (1840872).

Almost surely, 2^21464439 is an apocalyptic number.

21464439 is a deficient number, since it is larger than the sum of its proper divisors (7989513).

21464439 is a wasteful number, since it uses less digits than its factorization.

21464439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1006.

The product of its digits is 20736, while the sum is 33.

The square root of 21464439 is about 4632.9730195631. The cubic root of 21464439 is about 277.9114972836.

The spelling of 21464439 in words is "twenty-one million, four hundred sixty-four thousand, four hundred thirty-nine".