66249685 has 4 divisors (see below), whose sum is σ = 79499628. Its totient is φ = 52999744.

The previous prime is 66249671. The next prime is 66249691. The reversal of 66249685 is 58694266.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58694266 = 2 ⋅29347133.

It can be written as a sum of positive squares in 2 ways, for example, as 44849809 + 21399876 = 6697^2 + 4626^2 .

It is a cyclic number.

It is not a de Polignac number, because 66249685 - 2⁹ = 66249173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 6624964 + ... + 6624973.

It is an arithmetic number, because the mean of its divisors is an integer number (19874907).

Almost surely, 2^66249685 is an apocalyptic number.

It is an amenable number.

66249685 is a deficient number, since it is larger than the sum of its proper divisors (13249943).

66249685 is a wasteful number, since it uses less digits than its factorization.

66249685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13249942.

The product of its digits is 622080, while the sum is 46.

The square root of 66249685 is about 8139.3909477307. The cubic root of 66249685 is about 404.6329754212.

The spelling of 66249685 in words is "sixty-six million, two hundred forty-nine thousand, six hundred eighty-five".