21221340502 has 16 divisors (see below), whose sum is σ = 33514099200. Its totient is φ = 10050198120.

The previous prime is 21221340493. The next prime is 21221340509. The reversal of 21221340502 is 20504312212.

It is a happy number.

It is a super-2 number, since 2×21221340502² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221340509) 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, 145399 + ... + 252157.

It is an arithmetic number, because the mean of its divisors is an integer number (2094631200).

Almost surely, 2^21221340502 is an apocalyptic number.

21221340502 is a deficient number, since it is larger than the sum of its proper divisors (12292758698).

21221340502 is a wasteful number, since it uses less digits than its factorization.

21221340502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112011.

The product of its (nonzero) digits is 960, while the sum is 22.

Adding to 21221340502 its reverse (20504312212), we get a palindrome (41725652714).

The spelling of 21221340502 in words is "twenty-one billion, two hundred twenty-one million, three hundred forty thousand, five hundred two".