21533132540 has 12 divisors (see below), whose sum is σ = 45219578376. Its totient is φ = 8613253008.

The previous prime is 21533132513. The next prime is 21533132561. The reversal of 21533132540 is 4523133512.

It is a happy number.

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, 538328294 + ... + 538328333.

It is an arithmetic number, because the mean of its divisors is an integer number (3768298198).

Almost surely, 2^21533132540 is an apocalyptic number.

21533132540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21533132540 is an abundant number, since it is smaller than the sum of its proper divisors (23686445836).

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

21533132540 is a wasteful number, since it uses less digits than its factorization.

21533132540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1076656636 (or 1076656634 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 29.

The spelling of 21533132540 in words is "twenty-one billion, five hundred thirty-three million, one hundred thirty-two thousand, five hundred forty".