21034215 has 16 divisors (see below), whose sum is σ = 37394400. Its totient is φ = 11218176.

The previous prime is 21034201. The next prime is 21034229. The reversal of 21034215 is 51243012.

It is an interprime number because it is at equal distance from previous prime (21034201) and next prime (21034229).

It is not a de Polignac number, because 21034215 - 2⁴ = 21034199 is a prime.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 77770 + ... + 78039.

It is an arithmetic number, because the mean of its divisors is an integer number (2337150).

Almost surely, 2^21034215 is an apocalyptic number.

21034215 is a deficient number, since it is larger than the sum of its proper divisors (16360185).

21034215 is a wasteful number, since it uses less digits than its factorization.

21034215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155823 (or 155817 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21034215 is about 4586.3073381534. The cubic root of 21034215 is about 276.0421721948.

Adding to 21034215 its reverse (51243012), we get a palindrome (72277227).

The spelling of 21034215 in words is "twenty-one million, thirty-four thousand, two hundred fifteen".