66949687 has 16 divisors (see below), whose sum is σ = 79680832. Its totient is φ = 55054080.

The previous prime is 66949681. The next prime is 66949693. The reversal of 66949687 is 78694966.

It is an interprime number because it is at equal distance from previous prime (66949681) and next prime (66949693).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66949687 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66949681) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 17137 + ... + 20677.

It is an arithmetic number, because the mean of its divisors is an integer number (4980052).

Almost surely, 2^66949687 is an apocalyptic number.

66949687 is a deficient number, since it is larger than the sum of its proper divisors (12731145).

66949687 is a wasteful number, since it uses less digits than its factorization.

66949687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3658.

The product of its digits is 3919104, while the sum is 55.

The square root of 66949687 is about 8182.2788390521. The cubic root of 66949687 is about 406.0531185808.

The spelling of 66949687 in words is "sixty-six million, nine hundred forty-nine thousand, six hundred eighty-seven".