12205721156 has 18 divisors (see below), whose sum is σ = 21883524558. Its totient is φ = 5953320160.

The previous prime is 12205721131. The next prime is 12205721159. The reversal of 12205721156 is 65112750221.

It can be written as a sum of positive squares in only one way, i.e., 7442512900 + 4763208256 = 86270^2 + 69016^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12205721159) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1410515 + ... + 1419141.

Almost surely, 2^12205721156 is an apocalyptic number.

It is an amenable number.

12205721156 is a deficient number, since it is larger than the sum of its proper divisors (9677803402).

12205721156 is an frugal number, since it uses more digits than its factorization.

12205721156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17299 (or 8670 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 32.

The spelling of 12205721156 in words is "twelve billion, two hundred five million, seven hundred twenty-one thousand, one hundred fifty-six".