21392800000 has 648 divisors, whose sum is σ = 66896796456. Its totient is φ = 6758400000.

The previous prime is 21392799977. The next prime is 21392800003. The reversal of 21392800000 is 829312.

It can be written as a sum of positive squares in 12 ways, for example, as 21390817536 + 1982464 = 146256^2 + 1408^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21392800003) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1258399992 + ... + 1258400008.

It is an arithmetic number, because the mean of its divisors is an integer number (103235797).

Almost surely, 2^21392800000 is an apocalyptic number.

21392800000 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 21392800000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33448398228).

21392800000 is an abundant number, since it is smaller than the sum of its proper divisors (45503996456).

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

21392800000 is an equidigital number, since it uses as much as digits as its factorization.

21392800000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93 (or 48 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The spelling of 21392800000 in words is "twenty-one billion, three hundred ninety-two million, eight hundred thousand".