66947787 has 12 divisors (see below), whose sum is σ = 98760480. Its totient is φ = 43681968.

The previous prime is 66947767. The next prime is 66947801. The reversal of 66947787 is 78774966.

It is not a de Polignac number, because 66947787 - 2⁶ = 66947723 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66947707) 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 11 ways as a sum of consecutive naturals, for example, 78712 + ... + 79557.

It is an arithmetic number, because the mean of its divisors is an integer number (8230040).

Almost surely, 2^66947787 is an apocalyptic number.

66947787 is a deficient number, since it is larger than the sum of its proper divisors (31812693).

66947787 is a wasteful number, since it uses less digits than its factorization.

66947787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158322 (or 158319 counting only the distinct ones).

The product of its digits is 3556224, while the sum is 54.

The square root of 66947787 is about 8182.1627336542. The cubic root of 66947787 is about 406.0492773469.

The spelling of 66947787 in words is "sixty-six million, nine hundred forty-seven thousand, seven hundred eighty-seven".