221388726960 has 280 divisors, whose sum is σ = 776687811120. Its totient is φ = 58658535936.

The previous prime is 221388726931. The next prime is 221388726967. The reversal of 221388726960 is 69627883122.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 221388726897 and 221388726906.

It is not an unprimeable number, because it can be changed into a prime (221388726967) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 9144151 + ... + 9168329.

Almost surely, 2^221388726960 is an apocalyptic number.

221388726960 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 221388726960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (388343905560).

221388726960 is an abundant number, since it is smaller than the sum of its proper divisors (555299084160).

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

221388726960 is a wasteful number, since it uses less digits than its factorization.

221388726960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24367 (or 24346 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The spelling of 221388726960 in words is "two hundred twenty-one billion, three hundred eighty-eight million, seven hundred twenty-six thousand, nine hundred sixty".