21181564248 has 64 divisors (see below), whose sum is σ = 59506755840. Its totient is φ = 6234036864.

The previous prime is 21181564247. The next prime is 21181564259. The reversal of 21181564248 is 84246518112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21181564247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1468686 + ... + 1483037.

It is an arithmetic number, because the mean of its divisors is an integer number (929793060).

Almost surely, 2^21181564248 is an apocalyptic number.

It is an amenable number.

21181564248 is an abundant number, since it is smaller than the sum of its proper divisors (38325191592).

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

21181564248 is a wasteful number, since it uses less digits than its factorization.

21181564248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2951768 (or 2951764 counting only the distinct ones).

The product of its digits is 122880, while the sum is 42.

The spelling of 21181564248 in words is "twenty-one billion, one hundred eighty-one million, five hundred sixty-four thousand, two hundred forty-eight".