221507669 has 4 divisors (see below), whose sum is σ = 221562444. Its totient is φ = 221452896.

The previous prime is 221507659. The next prime is 221507701. The reversal of 221507669 is 966705122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 966705122 = 2 ⋅483352561.

It can be written as a sum of positive squares in 2 ways, for example, as 134328100 + 87179569 = 11590^2 + 9337^2 .

It is a cyclic number.

It is not a de Polignac number, because 221507669 - 2⁸ = 221507413 is a prime.

It is a super-2 number, since 2×221507669² = 98131294851627122, 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 (221507659) 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, 20792 + ... + 29585.

It is an arithmetic number, because the mean of its divisors is an integer number (55390611).

Almost surely, 2^221507669 is an apocalyptic number.

It is an amenable number.

221507669 is a deficient number, since it is larger than the sum of its proper divisors (54775).

221507669 is an equidigital number, since it uses as much as digits as its factorization.

221507669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54774.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 221507669 is about 14883.1337090009. The cubic root of 221507669 is about 605.0569524966.

The spelling of 221507669 in words is "two hundred twenty-one million, five hundred seven thousand, six hundred sixty-nine".