106661221 has 4 divisors (see below), whose sum is σ = 106747200. Its totient is φ = 106575244.

The previous prime is 106661209. The next prime is 106661227. The reversal of 106661221 is 122166601.

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 a cyclic number.

It is not a de Polignac number, because 106661221 - 2⁹ = 106660709 is a prime.

It is a super-2 number, since 2×106661221² = 22753232130421682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (106661227) 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, 41101 + ... + 43618.

It is an arithmetic number, because the mean of its divisors is an integer number (26686800).

Almost surely, 2^106661221 is an apocalyptic number.

It is an amenable number.

106661221 is a deficient number, since it is larger than the sum of its proper divisors (85979).

106661221 is an equidigital number, since it uses as much as digits as its factorization.

106661221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85978.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 106661221 is about 10327.6919493176. The cubic root of 106661221 is about 474.2443697716.

The spelling of 106661221 in words is "one hundred six million, six hundred sixty-one thousand, two hundred twenty-one".