21669558912 has 256 divisors, whose sum is σ = 68017190400. Its totient is φ = 6768230400.

The previous prime is 21669558863. The next prime is 21669558941. The reversal of 21669558912 is 21985596612.

21669558912 is a `hidden beast` number, since 2 + 16 + 69 + 558 + 9 + 12 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15921112 + ... + 15922472.

It is an arithmetic number, because the mean of its divisors is an integer number (265692150).

Almost surely, 2^21669558912 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21669558912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34008595200).

21669558912 is an abundant number, since it is smaller than the sum of its proper divisors (46347631488).

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

21669558912 is a wasteful number, since it uses less digits than its factorization.

21669558912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1672 (or 1654 counting only the distinct ones).

The product of its digits is 2332800, while the sum is 54.

The spelling of 21669558912 in words is "twenty-one billion, six hundred sixty-nine million, five hundred fifty-eight thousand, nine hundred twelve".