21521122 has 8 divisors (see below), whose sum is σ = 36893376. Its totient is φ = 9223332.

The previous prime is 21521117. The next prime is 21521141. The reversal of 21521122 is 22112512.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 21521096 and 21521105.

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, 768598 + ... + 768625.

It is an arithmetic number, because the mean of its divisors is an integer number (4611672).

Almost surely, 2^21521122 is an apocalyptic number.

21521122 is a deficient number, since it is larger than the sum of its proper divisors (15372254).

21521122 is a wasteful number, since it uses less digits than its factorization.

21521122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1537232.

The product of its digits is 80, while the sum is 16.

The square root of 21521122 is about 4639.0863324581. The cubic root of 21521122 is about 278.1559172296.

Adding to 21521122 its reverse (22112512), we get a palindrome (43633634).

The spelling of 21521122 in words is "twenty-one million, five hundred twenty-one thousand, one hundred twenty-two".