66613725 has 96 divisors (see below), whose sum is σ = 131241600. Its totient is φ = 33062400.

The previous prime is 66613721. The next prime is 66613759. The reversal of 66613725 is 52731666.

It is not a de Polignac number, because 66613725 - 2² = 66613721 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66613725.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66613721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 802534 + ... + 802616.

It is an arithmetic number, because the mean of its divisors is an integer number (1367100).

Almost surely, 2^66613725 is an apocalyptic number.

It is an amenable number.

66613725 is a deficient number, since it is larger than the sum of its proper divisors (64627875).

66613725 is a wasteful number, since it uses less digits than its factorization.

66613725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172 (or 161 counting only the distinct ones).

The product of its digits is 45360, while the sum is 36.

The square root of 66613725 is about 8161.7231636463. The cubic root of 66613725 is about 405.3727706433.

The spelling of 66613725 in words is "sixty-six million, six hundred thirteen thousand, seven hundred twenty-five".