221980691 has 4 divisors (see below), whose sum is σ = 222043800. Its totient is φ = 221917584.

The previous prime is 221980673. The next prime is 221980697. The reversal of 221980691 is 196089122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221980691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221980697) 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 3 ways as a sum of consecutive naturals, for example, 25946 + ... + 33423.

It is an arithmetic number, because the mean of its divisors is an integer number (55510950).

Almost surely, 2^221980691 is an apocalyptic number.

221980691 is a deficient number, since it is larger than the sum of its proper divisors (63109).

221980691 is an equidigital number, since it uses as much as digits as its factorization.

221980691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63108.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 221980691 is about 14899.0164440476. The cubic root of 221980691 is about 605.4873390460.

The spelling of 221980691 in words is "two hundred twenty-one million, nine hundred eighty thousand, six hundred ninety-one".