66636973 has 4 divisors (see below), whose sum is σ = 71762908. Its totient is φ = 61511040.

The previous prime is 66636961. The next prime is 66636989. The reversal of 66636973 is 37963666.

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 45724644 + 20912329 = 6762^2 + 4573^2 .

It is a cyclic number.

It is not a de Polignac number, because 66636973 - 2¹³ = 66628781 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 (66636943) 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, 2562948 + ... + 2562973.

It is an arithmetic number, because the mean of its divisors is an integer number (17940727).

Almost surely, 2^66636973 is an apocalyptic number.

It is an amenable number.

66636973 is a deficient number, since it is larger than the sum of its proper divisors (5125935).

66636973 is a wasteful number, since it uses less digits than its factorization.

66636973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5125934.

The product of its digits is 734832, while the sum is 46.

The square root of 66636973 is about 8163.1472484575. The cubic root of 66636973 is about 405.4199231385.

The spelling of 66636973 in words is "sixty-six million, six hundred thirty-six thousand, nine hundred seventy-three".