21458017 has 4 divisors (see below), whose sum is σ = 24523456. Its totient is φ = 18392580.

The previous prime is 21458009. The next prime is 21458027. The reversal of 21458017 is 71085412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21458017 - 2³ = 21458009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21458027) 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, 1532709 + ... + 1532722.

It is an arithmetic number, because the mean of its divisors is an integer number (6130864).

Almost surely, 2^21458017 is an apocalyptic number.

It is an amenable number.

21458017 is a deficient number, since it is larger than the sum of its proper divisors (3065439).

21458017 is an equidigital number, since it uses as much as digits as its factorization.

21458017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3065438.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 21458017 is about 4632.2798922345. The cubic root of 21458017 is about 277.8837781701.

The spelling of 21458017 in words is "twenty-one million, four hundred fifty-eight thousand, seventeen".