21513122 has 16 divisors (see below), whose sum is σ = 33384960. Its totient is φ = 10390848.

The previous prime is 21513113. The next prime is 21513127. The reversal of 21513122 is 22131512.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21513122.

It is not an unprimeable number, because it can be changed into a prime (21513127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5978 + ... + 8874.

It is an arithmetic number, because the mean of its divisors is an integer number (2086560).

Almost surely, 2^21513122 is an apocalyptic number.

21513122 is a deficient number, since it is larger than the sum of its proper divisors (11871838).

21513122 is a wasteful number, since it uses less digits than its factorization.

21513122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3025.

The product of its digits is 120, while the sum is 17.

The square root of 21513122 is about 4638.2240135638. The cubic root of 21513122 is about 278.1214468595.

Adding to 21513122 its reverse (22131512), we get a palindrome (43644634).

The spelling of 21513122 in words is "twenty-one million, five hundred thirteen thousand, one hundred twenty-two".