21986761344 has 64 divisors (see below), whose sum is σ = 58451336640. Its totient is φ = 7322771456.

The previous prime is 21986761343. The next prime is 21986761387. The reversal of 21986761344 is 44316768912.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21986761343) 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, 446224 + ... + 493040.

It is an arithmetic number, because the mean of its divisors is an integer number (913302135).

Almost surely, 2^21986761344 is an apocalyptic number.

21986761344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21986761344 is an abundant number, since it is smaller than the sum of its proper divisors (36464575296).

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

21986761344 is a wasteful number, since it uses less digits than its factorization.

21986761344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48057 (or 48045 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 51.

The spelling of 21986761344 in words is "twenty-one billion, nine hundred eighty-six million, seven hundred sixty-one thousand, three hundred forty-four".