669789021 has 8 divisors (see below), whose sum is σ = 974238624. Its totient is φ = 405932720.

The previous prime is 669789011. The next prime is 669789061. The reversal of 669789021 is 120987966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 669789021 - 2⁵ = 669788989 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669789011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10148286 + ... + 10148351.

It is an arithmetic number, because the mean of its divisors is an integer number (121779828).

Almost surely, 2^669789021 is an apocalyptic number.

It is an amenable number.

669789021 is a deficient number, since it is larger than the sum of its proper divisors (304449603).

669789021 is a wasteful number, since it uses less digits than its factorization.

669789021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20296651.

The product of its (nonzero) digits is 326592, while the sum is 48.

The square root of 669789021 is about 25880.2824752745. The cubic root of 669789021 is about 874.9421549788.

The spelling of 669789021 in words is "six hundred sixty-nine million, seven hundred eighty-nine thousand, twenty-one".