21458513 has 4 divisors (see below), whose sum is σ = 21478128. Its totient is φ = 21438900.

The previous prime is 21458453. The next prime is 21458527. The reversal of 21458513 is 31585412.

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 21458513 - 2⁶ = 21458449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21452513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8063 + ... + 10388.

It is an arithmetic number, because the mean of its divisors is an integer number (5369532).

Almost surely, 2^21458513 is an apocalyptic number.

It is an amenable number.

21458513 is a deficient number, since it is larger than the sum of its proper divisors (19615).

21458513 is a wasteful number, since it uses less digits than its factorization.

21458513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19614.

The product of its digits is 4800, while the sum is 29.

The square root of 21458513 is about 4632.3334292773. Note that the first 3 decimals coincide. The cubic root of 21458513 is about 277.8859192392.

The spelling of 21458513 in words is "twenty-one million, four hundred fifty-eight thousand, five hundred thirteen".