66704621 has 4 divisors (see below), whose sum is σ = 67316700. Its totient is φ = 66092544.

The previous prime is 66704579. The next prime is 66704629. The reversal of 66704621 is 12640766.

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 29311396 + 37393225 = 5414^2 + 6115^2 .

It is a cyclic number.

It is not a de Polignac number, because 66704621 - 2⁶ = 66704557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66704629) 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, 305876 + ... + 306093.

It is an arithmetic number, because the mean of its divisors is an integer number (16829175).

Almost surely, 2^66704621 is an apocalyptic number.

It is an amenable number.

66704621 is a deficient number, since it is larger than the sum of its proper divisors (612079).

66704621 is a wasteful number, since it uses less digits than its factorization.

66704621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 612078.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 66704621 is about 8167.2896973231. The cubic root of 66704621 is about 405.5570670808.

The spelling of 66704621 in words is "sixty-six million, seven hundred four thousand, six hundred twenty-one".