21861923959 has 8 divisors (see below), whose sum is σ = 24154351200. Its totient is φ = 19681322496.

The previous prime is 21861923953. The next prime is 21861923977. The reversal of 21861923959 is 95932916812.

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 21861923959 - 2⁵ = 21861923927 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 (21861923953) 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, 27956034 + ... + 27956815.

It is an arithmetic number, because the mean of its divisors is an integer number (3019293900).

Almost surely, 2^21861923959 is an apocalyptic number.

21861923959 is a deficient number, since it is larger than the sum of its proper divisors (2292427241).

21861923959 is a wasteful number, since it uses less digits than its factorization.

21861923959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55912889.

The product of its digits is 2099520, while the sum is 55.

The spelling of 21861923959 in words is "twenty-one billion, eight hundred sixty-one million, nine hundred twenty-three thousand, nine hundred fifty-nine".