66636669 has 16 divisors (see below), whose sum is σ = 97890624. Its totient is φ = 39984000.

The previous prime is 66636649. The next prime is 66636677. The reversal of 66636669 is 96663666.

It is not a de Polignac number, because 66636669 - 2²⁰ = 65588093 is a prime.

It is a super-2 number, since 2×66636669² = 8880891310831122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66636649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6664 + ... + 13329.

It is an arithmetic number, because the mean of its divisors is an integer number (6118164).

Almost surely, 2^66636669 is an apocalyptic number.

It is an amenable number.

66636669 is a deficient number, since it is larger than the sum of its proper divisors (31253955).

66636669 is a wasteful number, since it uses less digits than its factorization.

66636669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20108.

The product of its digits is 1259712, while the sum is 48.

The square root of 66636669 is about 8163.1286281670. The cubic root of 66636669 is about 405.4193066247.

It can be divided in two parts, 666366 and 69, that added together give a triangular number (666435 = T₁₁₅₄).

The spelling of 66636669 in words is "sixty-six million, six hundred thirty-six thousand, six hundred sixty-nine".