66631249 has 4 divisors (see below), whose sum is σ = 66789940. Its totient is φ = 66472560.

The previous prime is 66631223. The next prime is 66631277. The reversal of 66631249 is 94213666.

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 9734400 + 56896849 = 3120^2 + 7543^2 .

It is a cyclic number.

It is not a de Polignac number, because 66631249 - 2²¹ = 64534097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66631549) 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, 78714 + ... + 79555.

It is an arithmetic number, because the mean of its divisors is an integer number (16697485).

Almost surely, 2^66631249 is an apocalyptic number.

It is an amenable number.

66631249 is a deficient number, since it is larger than the sum of its proper divisors (158691).

66631249 is a wasteful number, since it uses less digits than its factorization.

66631249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158690.

The product of its digits is 46656, while the sum is 37.

The square root of 66631249 is about 8162.7966408578. The cubic root of 66631249 is about 405.4083145175.

The spelling of 66631249 in words is "sixty-six million, six hundred thirty-one thousand, two hundred forty-nine".