21214415 has 4 divisors (see below), whose sum is σ = 25457304. Its totient is φ = 16971528.

The previous prime is 21214381. The next prime is 21214429. The reversal of 21214415 is 51441212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21214415 - 2⁸ = 21214159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2121437 + ... + 2121446.

It is an arithmetic number, because the mean of its divisors is an integer number (6364326).

Almost surely, 2^21214415 is an apocalyptic number.

21214415 is a deficient number, since it is larger than the sum of its proper divisors (4242889).

21214415 is an equidigital number, since it uses as much as digits as its factorization.

21214415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4242888.

The product of its digits is 320, while the sum is 20.

The square root of 21214415 is about 4605.9108762546. The cubic root of 21214415 is about 276.8282156785.

Adding to 21214415 its reverse (51441212), we get a palindrome (72655627).

The spelling of 21214415 in words is "twenty-one million, two hundred fourteen thousand, four hundred fifteen".