66669669 has 24 divisors (see below), whose sum is σ = 108570560. Its totient is φ = 40403880.

The previous prime is 66669619. The next prime is 66669683. The reversal of 66669669 is 96696666.

It is not a de Polignac number, because 66669669 - 2⁷ = 66669541 is a prime.

It is a super-2 number, since 2×66669669² = 8889689529139122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66669619) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6937 + ... + 13470.

Almost surely, 2^66669669 is an apocalyptic number.

It is an amenable number.

66669669 is a deficient number, since it is larger than the sum of its proper divisors (41900891).

66669669 is a wasteful number, since it uses less digits than its factorization.

66669669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20438 (or 20421 counting only the distinct ones).

The product of its digits is 3779136, while the sum is 54.

The square root of 66669669 is about 8165.1496618249. The cubic root of 66669669 is about 405.4862198795.

The spelling of 66669669 in words is "sixty-six million, six hundred sixty-nine thousand, six hundred sixty-nine".