66994287 has 16 divisors (see below), whose sum is σ = 93014880. Its totient is φ = 42854400.

The previous prime is 66994273. The next prime is 66994303. The reversal of 66994287 is 78249966.

It is a happy number.

It is not a de Polignac number, because 66994287 - 2¹⁸ = 66732143 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66994237) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3039 + ... + 11967.

It is an arithmetic number, because the mean of its divisors is an integer number (5813430).

Almost surely, 2^66994287 is an apocalyptic number.

66994287 is a deficient number, since it is larger than the sum of its proper divisors (26020593).

66994287 is a wasteful number, since it uses less digits than its factorization.

66994287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9034.

The product of its digits is 1306368, while the sum is 51.

The square root of 66994287 is about 8185.0037874151. The cubic root of 66994287 is about 406.1432656247.

The spelling of 66994287 in words is "sixty-six million, nine hundred ninety-four thousand, two hundred eighty-seven".