221390447 has 8 divisors (see below), whose sum is σ = 227283840. Its totient is φ = 215520640.

The previous prime is 221390441. The next prime is 221390453. The reversal of 221390447 is 744093122.

It is an interprime number because it is at equal distance from previous prime (221390441) and next prime (221390453).

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 221390447 - 2¹² = 221386351 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221390441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14003 + ... + 25275.

It is an arithmetic number, because the mean of its divisors is an integer number (28410480).

Almost surely, 2^221390447 is an apocalyptic number.

221390447 is a deficient number, since it is larger than the sum of its proper divisors (5893393).

221390447 is a wasteful number, since it uses less digits than its factorization.

221390447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11793.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 221390447 is about 14879.1951059189. The cubic root of 221390447 is about 604.9502014882.

The spelling of 221390447 in words is "two hundred twenty-one million, three hundred ninety thousand, four hundred forty-seven".