21401115564 has 24 divisors (see below), whose sum is σ = 49976801280. Its totient is φ = 7127867344.

The previous prime is 21401115559. The next prime is 21401115581. The reversal of 21401115564 is 46551110412.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 714444 + ... + 743795.

It is an arithmetic number, because the mean of its divisors is an integer number (2082366720).

Almost surely, 2^21401115564 is an apocalyptic number.

It is an amenable number.

21401115564 is an abundant number, since it is smaller than the sum of its proper divisors (28575685716).

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

21401115564 is a wasteful number, since it uses less digits than its factorization.

21401115564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1459469 (or 1459467 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 30.

Adding to 21401115564 its reverse (46551110412), we get a palindrome (67952225976).

The spelling of 21401115564 in words is "twenty-one billion, four hundred one million, one hundred fifteen thousand, five hundred sixty-four".