21240827544 has 16 divisors (see below), whose sum is σ = 53102068920. Its totient is φ = 7080275840.

The previous prime is 21240827527. The next prime is 21240827563. The reversal of 21240827544 is 44572804212.

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, 442517217 + ... + 442517264.

Almost surely, 2^21240827544 is an apocalyptic number.

21240827544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21240827544 is an abundant number, since it is smaller than the sum of its proper divisors (31861241376).

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

21240827544 is a wasteful number, since it uses less digits than its factorization.

21240827544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 885034490 (or 885034486 counting only the distinct ones).

The product of its (nonzero) digits is 143360, while the sum is 39.

The spelling of 21240827544 in words is "twenty-one billion, two hundred forty million, eight hundred twenty-seven thousand, five hundred forty-four".