669026621 has 4 divisors (see below), whose sum is σ = 671178144. Its totient is φ = 666875100.

The previous prime is 669026591. The next prime is 669026629. The reversal of 669026621 is 126620966.

669026621 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 669026621 - 2¹⁰ = 669025597 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 (669026629) 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, 1075295 + ... + 1075916.

It is an arithmetic number, because the mean of its divisors is an integer number (167794536).

Almost surely, 2^669026621 is an apocalyptic number.

It is an amenable number.

669026621 is a deficient number, since it is larger than the sum of its proper divisors (2151523).

669026621 is a wasteful number, since it uses less digits than its factorization.

669026621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2151522.

The product of its (nonzero) digits is 46656, while the sum is 38.

The square root of 669026621 is about 25865.5489212968. The cubic root of 669026621 is about 874.6100557980.

The spelling of 669026621 in words is "six hundred sixty-nine million, twenty-six thousand, six hundred twenty-one".