21458039 has 4 divisors (see below), whose sum is σ = 22038024. Its totient is φ = 20878056.

The previous prime is 21458033. The next prime is 21458069. The reversal of 21458039 is 93085412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21458039 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21457996 and 21458014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21458033) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 289937 + ... + 290010.

It is an arithmetic number, because the mean of its divisors is an integer number (5509506).

Almost surely, 2^21458039 is an apocalyptic number.

21458039 is a deficient number, since it is larger than the sum of its proper divisors (579985).

21458039 is an equidigital number, since it uses as much as digits as its factorization.

21458039 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579984.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 21458039 is about 4632.2822668745. The cubic root of 21458039 is about 277.8838731376.

The spelling of 21458039 in words is "twenty-one million, four hundred fifty-eight thousand, thirty-nine".