66956287 has 4 divisors (see below), whose sum is σ = 67646656. Its totient is φ = 66265920.

The previous prime is 66956237. The next prime is 66956291. The reversal of 66956287 is 78265966.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66956287 - 2²³ = 58567679 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66956287.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66956207) 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, 345039 + ... + 345232.

It is an arithmetic number, because the mean of its divisors is an integer number (16911664).

Almost surely, 2^66956287 is an apocalyptic number.

66956287 is a deficient number, since it is larger than the sum of its proper divisors (690369).

66956287 is an equidigital number, since it uses as much as digits as its factorization.

66956287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 690368.

The product of its digits is 1088640, while the sum is 49.

The square root of 66956287 is about 8182.6821397388. The cubic root of 66956287 is about 406.0664612497.

The spelling of 66956287 in words is "sixty-six million, nine hundred fifty-six thousand, two hundred eighty-seven".