66666987 has 6 divisors (see below), whose sum is σ = 96296772. Its totient is φ = 44444652.

The previous prime is 66666983. The next prime is 66667037. The reversal of 66666987 is 78966666.

It is not a de Polignac number, because 66666987 - 2² = 66666983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66666983) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3703713 + ... + 3703730.

It is an arithmetic number, because the mean of its divisors is an integer number (16049462).

Almost surely, 2^66666987 is an apocalyptic number.

66666987 is a deficient number, since it is larger than the sum of its proper divisors (29629785).

66666987 is a wasteful number, since it uses less digits than its factorization.

66666987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7407449 (or 7407446 counting only the distinct ones).

The product of its digits is 3919104, while the sum is 54.

The square root of 66666987 is about 8164.9854255841. The cubic root of 66666987 is about 405.4807824812.

The spelling of 66666987 in words is "sixty-six million, six hundred sixty-six thousand, nine hundred eighty-seven".