21879009600 has 672 divisors, whose sum is σ = 85190380800. Its totient is φ = 4913233920.

The previous prime is 21879009577. The next prime is 21879009613. The reversal of 21879009600 is 690097812.

It is a tau number, because it is divible by the number of its divisors (672).

It is a super-2 number, since 2×21879009600² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 159700732 + ... + 159700868.

It is an arithmetic number, because the mean of its divisors is an integer number (126771400).

Almost surely, 2^21879009600 is an apocalyptic number.

21879009600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21879009600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42595190400).

21879009600 is an abundant number, since it is smaller than the sum of its proper divisors (63311371200).

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

21879009600 is a wasteful number, since it uses less digits than its factorization.

21879009600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 42.

The spelling of 21879009600 in words is "twenty-one billion, eight hundred seventy-nine million, nine thousand, six hundred".