669556221 has 4 divisors (see below), whose sum is σ = 892741632. Its totient is φ = 446370812.

The previous prime is 669556213. The next prime is 669556229. The reversal of 669556221 is 122655966.

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 (669556213) and next prime (669556229).

It is a cyclic number.

It is not a de Polignac number, because 669556221 - 2³ = 669556213 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669556229) 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, 111592701 + ... + 111592706.

It is an arithmetic number, because the mean of its divisors is an integer number (223185408).

Almost surely, 2^669556221 is an apocalyptic number.

It is an amenable number.

669556221 is a deficient number, since it is larger than the sum of its proper divisors (223185411).

669556221 is a wasteful number, since it uses less digits than its factorization.

669556221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223185410.

The product of its digits is 194400, while the sum is 42.

The square root of 669556221 is about 25875.7844518770. The cubic root of 669556221 is about 874.8407747279.

The spelling of 669556221 in words is "six hundred sixty-nine million, five hundred fifty-six thousand, two hundred twenty-one".