21023449 has 8 divisors (see below), whose sum is σ = 21998592. Its totient is φ = 20053440.

The previous prime is 21023419. The next prime is 21023459. The reversal of 21023449 is 94432012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21023449 - 2⁵ = 21023417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21023419) 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, 8904 + ... + 11014.

It is an arithmetic number, because the mean of its divisors is an integer number (2749824).

Almost surely, 2^21023449 is an apocalyptic number.

It is an amenable number.

21023449 is a deficient number, since it is larger than the sum of its proper divisors (975143).

21023449 is a wasteful number, since it uses less digits than its factorization.

21023449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2567.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 21023449 is about 4585.1334767921. The cubic root of 21023449 is about 275.9950683499.

The spelling of 21023449 in words is "twenty-one million, twenty-three thousand, four hundred forty-nine".