21366155156 has 6 divisors (see below), whose sum is σ = 37390771530. Its totient is φ = 10683077576.

The previous prime is 21366155149. The next prime is 21366155197. The reversal of 21366155156 is 65155166312.

It can be written as a sum of positive squares in only one way, i.e., 19834215556 + 1531939600 = 140834^2 + 39140^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2670769391 + ... + 2670769398.

It is an arithmetic number, because the mean of its divisors is an integer number (6231795255).

Almost surely, 2^21366155156 is an apocalyptic number.

It is an amenable number.

21366155156 is a deficient number, since it is larger than the sum of its proper divisors (16024616374).

21366155156 is a wasteful number, since it uses less digits than its factorization.

21366155156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5341538793 (or 5341538791 counting only the distinct ones).

The product of its digits is 162000, while the sum is 41.

The spelling of 21366155156 in words is "twenty-one billion, three hundred sixty-six million, one hundred fifty-five thousand, one hundred fifty-six".