21389315 has 8 divisors (see below), whose sum is σ = 27177120. Its totient is φ = 16104832.

The previous prime is 21389261. The next prime is 21389317. The reversal of 21389315 is 51398312.

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

It is a cyclic number.

It is not a de Polignac number, because 21389315 - 2⁸ = 21389059 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21389317) 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, 125735 + ... + 125904.

It is an arithmetic number, because the mean of its divisors is an integer number (3397140).

Almost surely, 2^21389315 is an apocalyptic number.

21389315 is a deficient number, since it is larger than the sum of its proper divisors (5787805).

21389315 is a wasteful number, since it uses less digits than its factorization.

21389315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251661.

The product of its digits is 6480, while the sum is 32.

The square root of 21389315 is about 4624.8583762100. The cubic root of 21389315 is about 277.5868948446.

The spelling of 21389315 in words is "twenty-one million, three hundred eighty-nine thousand, three hundred fifteen".