66573869 has 4 divisors (see below), whose sum is σ = 67321980. Its totient is φ = 65825760.

The previous prime is 66573851. The next prime is 66573877. The reversal of 66573869 is 96837566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 32058244 + 34515625 = 5662^2 + 5875^2 .

It is a cyclic number.

It is not a de Polignac number, because 66573869 - 2²⁴ = 49796653 is a prime.

It is a super-2 number, since 2×66573869² = 8864160067258322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66576869) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 373922 + ... + 374099.

It is an arithmetic number, because the mean of its divisors is an integer number (16830495).

Almost surely, 2^66573869 is an apocalyptic number.

It is an amenable number.

66573869 is a deficient number, since it is larger than the sum of its proper divisors (748111).

66573869 is an equidigital number, since it uses as much as digits as its factorization.

66573869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 748110.

The product of its digits is 1632960, while the sum is 50.

The square root of 66573869 is about 8159.2811570628. The cubic root of 66573869 is about 405.2919076257.

The spelling of 66573869 in words is "sixty-six million, five hundred seventy-three thousand, eight hundred sixty-nine".