221326290 has 128 divisors (see below), whose sum is σ = 612126720. Its totient is φ = 56873664.

The previous prime is 221326279. The next prime is 221326319. The reversal of 221326290 is 92623122.

221326290 is a `hidden beast` number, since 2 + 2 + 1 + 32 + 629 + 0 = 666.

221326290 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 1357749 + ... + 1357911.

It is an arithmetic number, because the mean of its divisors is an integer number (4782240).

Almost surely, 2^221326290 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221326290, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (306063360).

221326290 is an abundant number, since it is smaller than the sum of its proper divisors (390800430).

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

221326290 is a wasteful number, since it uses less digits than its factorization.

221326290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333 (or 327 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 221326290 is about 14877.0390199125. The cubic root of 221326290 is about 604.8917594305.

The spelling of 221326290 in words is "two hundred twenty-one million, three hundred twenty-six thousand, two hundred ninety".