21222154612 has 12 divisors (see below), whose sum is σ = 39323404260. Its totient is φ = 9986896256.

The previous prime is 21222154601. The next prime is 21222154619. The reversal of 21222154612 is 21645122212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18627882256 + 2594272356 = 136484^2 + 50934^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222154619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 156045187 + ... + 156045322.

It is an arithmetic number, because the mean of its divisors is an integer number (3276950355).

Almost surely, 2^21222154612 is an apocalyptic number.

It is an amenable number.

21222154612 is a deficient number, since it is larger than the sum of its proper divisors (18101249648).

21222154612 is a wasteful number, since it uses less digits than its factorization.

21222154612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312090530 (or 312090528 counting only the distinct ones).

The product of its digits is 3840, while the sum is 28.

Adding to 21222154612 its reverse (21645122212), we get a palindrome (42867276824).

The spelling of 21222154612 in words is "twenty-one billion, two hundred twenty-two million, one hundred fifty-four thousand, six hundred twelve".