221338746720 has 1296 divisors, whose sum is σ = 985534896528. Its totient is φ = 46558955520.

The previous prime is 221338746703. The next prime is 221338746751. The reversal of 221338746720 is 27647833122.

221338746720 is a `hidden beast` number, since 221 + 3 + 387 + 46 + 7 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1296).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 668696955 + ... + 668697285.

It is an arithmetic number, because the mean of its divisors is an integer number (760443593).

Almost surely, 2^221338746720 is an apocalyptic number.

221338746720 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 221338746720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (492767448264).

221338746720 is an abundant number, since it is smaller than the sum of its proper divisors (764196149808).

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

221338746720 is an equidigital number, since it uses as much as digits as its factorization.

221338746720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 397 (or 361 counting only the distinct ones).

The product of its (nonzero) digits is 677376, while the sum is 45.

The spelling of 221338746720 in words is "two hundred twenty-one billion, three hundred thirty-eight million, seven hundred forty-six thousand, seven hundred twenty".