66969864 has 48 divisors (see below), whose sum is σ = 195331500. Its totient is φ = 20605824.

The previous prime is 66969863. The next prime is 66969869. The reversal of 66969864 is 46896966.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 55800900 + 11168964 = 7470^2 + 3342^2 .

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 66969864.

It is not an unprimeable number, because it can be changed into a prime (66969863) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34839 + ... + 36710.

Almost surely, 2^66969864 is an apocalyptic number.

It is an amenable number.

66969864 is an abundant number, since it is smaller than the sum of its proper divisors (128361636).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66969864 is a wasteful number, since it uses less digits than its factorization.

66969864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71574 (or 71567 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 54.

The square root of 66969864 is about 8183.5117156390. The cubic root of 66969864 is about 406.0939059802.

The spelling of 66969864 in words is "sixty-six million, nine hundred sixty-nine thousand, eight hundred sixty-four".