21265036156 has 48 divisors (see below), whose sum is σ = 45929479680. Its totient is φ = 8389056960.

The previous prime is 21265036153. The next prime is 21265036157. The reversal of 21265036156 is 65163056212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21265036153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49311 + ... + 212041.

It is an arithmetic number, because the mean of its divisors is an integer number (956864160).

Almost surely, 2^21265036156 is an apocalyptic number.

21265036156 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21265036156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22964739840).

21265036156 is an abundant number, since it is smaller than the sum of its proper divisors (24664443524).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21265036156 is a wasteful number, since it uses less digits than its factorization.

21265036156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163114 (or 163112 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 37.

The spelling of 21265036156 in words is "twenty-one billion, two hundred sixty-five million, thirty-six thousand, one hundred fifty-six".