669266991 has 6 divisors (see below), whose sum is σ = 966719000. Its totient is φ = 446177988.

The previous prime is 669266971. The next prime is 669267019. The reversal of 669266991 is 199662966.

It is a happy number.

It is not a de Polignac number, because 669266991 - 2¹⁰ = 669265967 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 (669266951) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37181491 + ... + 37181508.

Almost surely, 2^669266991 is an apocalyptic number.

669266991 is a deficient number, since it is larger than the sum of its proper divisors (297452009).

669266991 is a wasteful number, since it uses less digits than its factorization.

669266991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74363005 (or 74363002 counting only the distinct ones).

The product of its digits is 1889568, while the sum is 54.

The square root of 669266991 is about 25870.1950321214. The cubic root of 669266991 is about 874.7147874784.

The spelling of 669266991 in words is "six hundred sixty-nine million, two hundred sixty-six thousand, nine hundred ninety-one".