21221514 has 40 divisors (see below), whose sum is σ = 48059748. Its totient is φ = 6998400.

The previous prime is 21221509. The next prime is 21221521. The reversal of 21221514 is 41512212.

It can be written as a sum of positive squares in 2 ways, for example, as 13286025 + 7935489 = 3645^2 + 2817^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15714 + ... + 17010.

Almost surely, 2^21221514 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21221514, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24029874).

21221514 is an abundant number, since it is smaller than the sum of its proper divisors (26838234).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21221514 is a wasteful number, since it uses less digits than its factorization.

21221514 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1412 (or 1403 counting only the distinct ones).

The product of its digits is 160, while the sum is 18.

The square root of 21221514 is about 4606.6814519782. The cubic root of 21221514 is about 276.8590906651.

Adding to 21221514 its reverse (41512212), we get a palindrome (62733726).

The spelling of 21221514 in words is "twenty-one million, two hundred twenty-one thousand, five hundred fourteen".