221245789 has 4 divisors (see below), whose sum is σ = 221708160. Its totient is φ = 220783420.

The previous prime is 221245771. The next prime is 221245807. The reversal of 221245789 is 987542122.

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 an interprime number because it is at equal distance from previous prime (221245771) and next prime (221245807).

It is a cyclic number.

It is not a de Polignac number, because 221245789 - 2⁵ = 221245757 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 (221245489) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 230467 + ... + 231424.

It is an arithmetic number, because the mean of its divisors is an integer number (55427040).

Almost surely, 2^221245789 is an apocalyptic number.

It is an amenable number.

221245789 is a deficient number, since it is larger than the sum of its proper divisors (462371).

221245789 is an equidigital number, since it uses as much as digits as its factorization.

221245789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462370.

The product of its digits is 80640, while the sum is 40.

The square root of 221245789 is about 14874.3332287535. Note that the first 3 decimals coincide. The cubic root of 221245789 is about 604.8184132766.

The spelling of 221245789 in words is "two hundred twenty-one million, two hundred forty-five thousand, seven hundred eighty-nine".