21392321280 has 576 divisors, whose sum is σ = 81547554816. Its totient is φ = 4723507200.

The previous prime is 21392321257. The next prime is 21392321309. The reversal of 21392321280 is 8212329312.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 690074865 + ... + 690074895.

It is an arithmetic number, because the mean of its divisors is an integer number (141575616).

Almost surely, 2^21392321280 is an apocalyptic number.

21392321280 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 21392321280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40773777408).

21392321280 is an abundant number, since it is smaller than the sum of its proper divisors (60155233536).

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

21392321280 is an equidigital number, since it uses as much as digits as its factorization.

21392321280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145 (or 69 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The spelling of 21392321280 in words is "twenty-one billion, three hundred ninety-two million, three hundred twenty-one thousand, two hundred eighty".