21479215 has 16 divisors (see below), whose sum is σ = 27256320. Its totient is φ = 16204320.

The previous prime is 21479209. The next prime is 21479221. The reversal of 21479215 is 51297412.

It is an interprime number because it is at equal distance from previous prime (21479209) and next prime (21479221).

It is a de Polignac number, because none of the positive numbers 2^k-21479215 is a prime.

It is a super-2 number, since 2×21479215² = 922713354032450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29182 + ... + 29908.

It is an arithmetic number, because the mean of its divisors is an integer number (1703520).

Almost surely, 2^21479215 is an apocalyptic number.

21479215 is a deficient number, since it is larger than the sum of its proper divisors (5777105).

21479215 is a wasteful number, since it uses less digits than its factorization.

21479215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1062.

The product of its digits is 5040, while the sum is 31.

The square root of 21479215 is about 4634.5674016029. The cubic root of 21479215 is about 277.9752535638.

The spelling of 21479215 in words is "twenty-one million, four hundred seventy-nine thousand, two hundred fifteen".