669226021 has 4 divisors (see below), whose sum is σ = 669823072. Its totient is φ = 668628972.

The previous prime is 669226013. The next prime is 669226027. The reversal of 669226021 is 120622966.

669226021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 669226021 - 2³ = 669226013 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 (669226027) 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, 296841 + ... + 299086.

It is an arithmetic number, because the mean of its divisors is an integer number (167455768).

Almost surely, 2^669226021 is an apocalyptic number.

It is an amenable number.

669226021 is a deficient number, since it is larger than the sum of its proper divisors (597051).

669226021 is a wasteful number, since it uses less digits than its factorization.

669226021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 597050.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 669226021 is about 25869.4031821378. The cubic root of 669226021 is about 874.6969382012.

Adding to 669226021 its reverse (120622966), we get a palindrome (789848987).

The spelling of 669226021 in words is "six hundred sixty-nine million, two hundred twenty-six thousand, twenty-one".