221790961 has 8 divisors (see below), whose sum is σ = 253847744. Its totient is φ = 189827280.

The previous prime is 221790941. The next prime is 221790967. The reversal of 221790961 is 169097122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221790961 - 2⁵ = 221790929 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221790961.

It is not an unprimeable number, because it can be changed into a prime (221790967) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 18090 + ... + 27763.

It is an arithmetic number, because the mean of its divisors is an integer number (31730968).

Almost surely, 2^221790961 is an apocalyptic number.

It is an amenable number.

221790961 is a deficient number, since it is larger than the sum of its proper divisors (32056783).

221790961 is an equidigital number, since it uses as much as digits as its factorization.

221790961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46551.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 221790961 is about 14892.6478841071. The cubic root of 221790961 is about 605.3147837103.

The spelling of 221790961 in words is "two hundred twenty-one million, seven hundred ninety thousand, nine hundred sixty-one".