221099997 has 4 divisors (see below), whose sum is σ = 294800000. Its totient is φ = 147399996.

The previous prime is 221099993. The next prime is 221099999. The reversal of 221099997 is 799990122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 221099997 - 2² = 221099993 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 (221099993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36849997 + ... + 36850002.

It is an arithmetic number, because the mean of its divisors is an integer number (73700000).

Almost surely, 2^221099997 is an apocalyptic number.

It is an amenable number.

221099997 is a deficient number, since it is larger than the sum of its proper divisors (73700003).

221099997 is an equidigital number, since it uses as much as digits as its factorization.

221099997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73700002.

The product of its (nonzero) digits is 183708, while the sum is 48.

The square root of 221099997 is about 14869.4316300254. The cubic root of 221099997 is about 604.6855338184.

The spelling of 221099997 in words is "two hundred twenty-one million, ninety-nine thousand, nine hundred ninety-seven".