21222372015 has 24 divisors (see below), whose sum is σ = 39615095520. Its totient is φ = 10447936704.

The previous prime is 21222372013. The next prime is 21222372029. The reversal of 21222372015 is 51027322212.

It is not a de Polignac number, because 21222372015 - 2¹ = 21222372013 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21222372015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222372013) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18138195 + ... + 18139364.

It is an arithmetic number, because the mean of its divisors is an integer number (1650628980).

Almost surely, 2^21222372015 is an apocalyptic number.

21222372015 is a deficient number, since it is larger than the sum of its proper divisors (18392723505).

21222372015 is a wasteful number, since it uses less digits than its factorization.

21222372015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36277583 (or 36277580 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

Adding to 21222372015 its reverse (51027322212), we get a palindrome (72249694227).

The spelling of 21222372015 in words is "twenty-one billion, two hundred twenty-two million, three hundred seventy-two thousand, fifteen".