21779200000 has 288 divisors, whose sum is σ = 56430606960. Its totient is φ = 8396800000.

The previous prime is 21779199973. The next prime is 21779200039. The reversal of 21779200000 is 297712.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 262399959 + ... + 262400041.

Almost surely, 2^21779200000 is an apocalyptic number.

21779200000 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 21779200000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28215303480).

21779200000 is an abundant number, since it is smaller than the sum of its proper divisors (34651406960).

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

21779200000 is an frugal number, since it uses more digits than its factorization.

21779200000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 28.

Adding to 21779200000 its reverse (297712), we get a palindrome (21779497712).

The spelling of 21779200000 in words is "twenty-one billion, seven hundred seventy-nine million, two hundred thousand".