21148763568 has 40 divisors (see below), whose sum is σ = 54640685808. Its totient is φ = 7048764672.

The previous prime is 21148763563. The next prime is 21148763609. The reversal of 21148763568 is 86536784112.

It is a self number, because there is not a number n which added to its sum of digits gives 21148763568.

It is not an unprimeable number, because it can be changed into a prime (21148763563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 500646 + ... + 541242.

Almost surely, 2^21148763568 is an apocalyptic number.

It is an amenable number.

21148763568 is an abundant number, since it is smaller than the sum of its proper divisors (33491922240).

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

21148763568 is a wasteful number, since it uses less digits than its factorization.

21148763568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51461 (or 51455 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 51.

The spelling of 21148763568 in words is "twenty-one billion, one hundred forty-eight million, seven hundred sixty-three thousand, five hundred sixty-eight".