21364521 has 8 divisors (see below), whose sum is σ = 28634400. Its totient is φ = 14168832.

The previous prime is 21364517. The next prime is 21364547. The reversal of 21364521 is 12546312.

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

It is not a de Polignac number, because 21364521 - 2² = 21364517 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21364491 and 21364500.

It is not an unprimeable number, because it can be changed into a prime (21364501) 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, 17871 + ... + 19028.

It is an arithmetic number, because the mean of its divisors is an integer number (3579300).

Almost surely, 2^21364521 is an apocalyptic number.

It is an amenable number.

21364521 is a deficient number, since it is larger than the sum of its proper divisors (7269879).

21364521 is a wasteful number, since it uses less digits than its factorization.

21364521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37095.

The product of its digits is 1440, while the sum is 24.

The square root of 21364521 is about 4622.1770844484. The cubic root of 21364521 is about 277.4795959350.

The spelling of 21364521 in words is "twenty-one million, three hundred sixty-four thousand, five hundred twenty-one".