21681379288 has 16 divisors (see below), whose sum is σ = 41751305280. Its totient is φ = 10547697888.

The previous prime is 21681379283. The next prime is 21681379297. The reversal of 21681379288 is 88297318612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21681379283) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36623656 + ... + 36624247.

It is an arithmetic number, because the mean of its divisors is an integer number (2609456580).

Almost surely, 2^21681379288 is an apocalyptic number.

It is an amenable number.

21681379288 is a deficient number, since it is larger than the sum of its proper divisors (20069925992).

21681379288 is a wasteful number, since it uses less digits than its factorization.

21681379288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73247946 (or 73247942 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 55.

The spelling of 21681379288 in words is "twenty-one billion, six hundred eighty-one million, three hundred seventy-nine thousand, two hundred eighty-eight".