21540233372 has 48 divisors (see below), whose sum is σ = 45103080960. Its totient is φ = 8805784512.

The previous prime is 21540233357. The next prime is 21540233383. The reversal of 21540233372 is 27333204512.

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 15 ways as a sum of consecutive naturals, for example, 92408 + ... + 227199.

It is an arithmetic number, because the mean of its divisors is an integer number (939647520).

Almost surely, 2^21540233372 is an apocalyptic number.

It is an amenable number.

21540233372 is an abundant number, since it is smaller than the sum of its proper divisors (23562847588).

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

21540233372 is a wasteful number, since it uses less digits than its factorization.

21540233372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 319730 (or 319728 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 32.

Adding to 21540233372 its reverse (27333204512), we get a palindrome (48873437884).

The spelling of 21540233372 in words is "twenty-one billion, five hundred forty million, two hundred thirty-three thousand, three hundred seventy-two".