221352390 has 96 divisors (see below), whose sum is σ = 673111296. Its totient is φ = 49412160.

The previous prime is 221352379. The next prime is 221352409. The reversal of 221352390 is 93253122.

221352390 is a `hidden beast` number, since 221 + 3 + 52 + 390 = 666.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 23005 + ... + 31175.

It is an arithmetic number, because the mean of its divisors is an integer number (7011576).

Almost surely, 2^221352390 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221352390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (336555648).

221352390 is an abundant number, since it is smaller than the sum of its proper divisors (451758906).

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

221352390 is a wasteful number, since it uses less digits than its factorization.

221352390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8234 (or 8231 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 221352390 is about 14877.9161847350. The cubic root of 221352390 is about 604.9155358715.

The spelling of 221352390 in words is "two hundred twenty-one million, three hundred fifty-two thousand, three hundred ninety".