21986138833 has 8 divisors (see below), whose sum is σ = 22034413800. Its totient is φ = 21937893120.

The previous prime is 21986138827. The next prime is 21986138861. The reversal of 21986138833 is 33883168912.

It can be written as a sum of positive squares in 4 ways, for example, as 327718609 + 21658420224 = 18103^2 + 147168^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21986138833 - 2²⁹ = 21449267921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21986138803) 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, 2185491 + ... + 2195527.

It is an arithmetic number, because the mean of its divisors is an integer number (2754301725).

Almost surely, 2^21986138833 is an apocalyptic number.

It is an amenable number.

21986138833 is a deficient number, since it is larger than the sum of its proper divisors (48274967).

21986138833 is a wasteful number, since it uses less digits than its factorization.

21986138833 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14627.

The product of its digits is 1492992, while the sum is 52.

The spelling of 21986138833 in words is "twenty-one billion, nine hundred eighty-six million, one hundred thirty-eight thousand, eight hundred thirty-three".