66172529 has 4 divisors (see below), whose sum is σ = 67079076. Its totient is φ = 65265984.

The previous prime is 66172511. The next prime is 66172531. The reversal of 66172529 is 92527166.

It is a happy number.

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 57410929 + 8761600 = 7577^2 + 2960^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66172529 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66172492 and 66172501.

It is not an unprimeable number, because it can be changed into a prime (66172549) 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, 453164 + ... + 453309.

It is an arithmetic number, because the mean of its divisors is an integer number (16769769).

Almost surely, 2^66172529 is an apocalyptic number.

It is an amenable number.

66172529 is a deficient number, since it is larger than the sum of its proper divisors (906547).

66172529 is an equidigital number, since it uses as much as digits as its factorization.

66172529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 906546.

The product of its digits is 45360, while the sum is 38.

The square root of 66172529 is about 8134.6499002723. The cubic root of 66172529 is about 404.4758325885.

The spelling of 66172529 in words is "sixty-six million, one hundred seventy-two thousand, five hundred twenty-nine".