21300621 has 8 divisors (see below), whose sum is σ = 28423200. Its totient is φ = 14189232.

The previous prime is 21300619. The next prime is 21300649. The reversal of 21300621 is 12600312.

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

It is not a de Polignac number, because 21300621 - 2¹ = 21300619 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21300621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21300421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4026 + ... + 7668.

It is an arithmetic number, because the mean of its divisors is an integer number (3552900).

Almost surely, 2^21300621 is an apocalyptic number.

It is an amenable number.

21300621 is a deficient number, since it is larger than the sum of its proper divisors (7122579).

21300621 is a wasteful number, since it uses less digits than its factorization.

21300621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5595.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 21300621 is about 4615.2595809987. The cubic root of 21300621 is about 277.2026780640.

Adding to 21300621 its reverse (12600312), we get a palindrome (33900933).

The spelling of 21300621 in words is "twenty-one million, three hundred thousand, six hundred twenty-one".