21328970861 has 8 divisors (see below), whose sum is σ = 23493872064. Its totient is φ = 19201720320.

The previous prime is 21328970849. The next prime is 21328970869. The reversal of 21328970861 is 16807982312.

It is a happy number.

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 21328970861 - 2²⁶ = 21261861997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21328970869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9411476 + ... + 9413741.

It is an arithmetic number, because the mean of its divisors is an integer number (2936734008).

Almost surely, 2^21328970861 is an apocalyptic number.

It is an amenable number.

21328970861 is a deficient number, since it is larger than the sum of its proper divisors (2164901203).

21328970861 is a wasteful number, since it uses less digits than its factorization.

21328970861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18825331.

The product of its (nonzero) digits is 290304, while the sum is 47.

The spelling of 21328970861 in words is "twenty-one billion, three hundred twenty-eight million, nine hundred seventy thousand, eight hundred sixty-one".