21541323156 has 12 divisors (see below), whose sum is σ = 50263087392. Its totient is φ = 7180441048.

The previous prime is 21541323143. The next prime is 21541323239. The reversal of 21541323156 is 65132314512.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21541323156² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 897555120 + ... + 897555143.

It is an arithmetic number, because the mean of its divisors is an integer number (4188590616).

Almost surely, 2^21541323156 is an apocalyptic number.

It is an amenable number.

21541323156 is an abundant number, since it is smaller than the sum of its proper divisors (28721764236).

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

21541323156 is a wasteful number, since it uses less digits than its factorization.

21541323156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1795110270 (or 1795110268 counting only the distinct ones).

The product of its digits is 21600, while the sum is 33.

Adding to 21541323156 its reverse (65132314512), we get a palindrome (86673637668).

The spelling of 21541323156 in words is "twenty-one billion, five hundred forty-one million, three hundred twenty-three thousand, one hundred fifty-six".