221901768 has 128 divisors (see below), whose sum is σ = 681321600. Its totient is φ = 67184640.

The previous prime is 221901761. The next prime is 221901781. The reversal of 221901768 is 867109122.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (221901761) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 191880 + ... + 193032.

It is an arithmetic number, because the mean of its divisors is an integer number (5322825).

Almost surely, 2^221901768 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221901768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (340660800).

221901768 is an abundant number, since it is smaller than the sum of its proper divisors (459419832).

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

221901768 is a wasteful number, since it uses less digits than its factorization.

221901768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1191 (or 1169 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 221901768 is about 14896.3676109312. The cubic root of 221901768 is about 605.4155722307.

The spelling of 221901768 in words is "two hundred twenty-one million, nine hundred one thousand, seven hundred sixty-eight".