66415249 has 4 divisors (see below), whose sum is σ = 68705460. Its totient is φ = 64125040.

The previous prime is 66415229. The next prime is 66415253. The reversal of 66415249 is 94251466.

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 11950849 + 54464400 = 3457^2 + 7380^2 .

It is a cyclic number.

It is not a de Polignac number, because 66415249 - 2¹³ = 66407057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66415229) 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, 1145062 + ... + 1145119.

It is an arithmetic number, because the mean of its divisors is an integer number (17176365).

Almost surely, 2^66415249 is an apocalyptic number.

It is an amenable number.

66415249 is a deficient number, since it is larger than the sum of its proper divisors (2290211).

66415249 is a wasteful number, since it uses less digits than its factorization.

66415249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2290210.

The product of its digits is 51840, while the sum is 37.

The square root of 66415249 is about 8149.5551412332. Note that the first 3 decimals coincide. The cubic root of 66415249 is about 404.9697665792.

The spelling of 66415249 in words is "sixty-six million, four hundred fifteen thousand, two hundred forty-nine".