66065987 has 8 divisors (see below), whose sum is σ = 71571360. Its totient is φ = 60981960.

The previous prime is 66065977. The next prime is 66066043. The reversal of 66065987 is 78956066.

It is not a de Polignac number, because 66065987 - 2⁸ = 66065731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66065917) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12839 + ... + 17232.

It is an arithmetic number, because the mean of its divisors is an integer number (8946420).

Almost surely, 2^66065987 is an apocalyptic number.

66065987 is a deficient number, since it is larger than the sum of its proper divisors (5505373).

66065987 is an equidigital number, since it uses as much as digits as its factorization.

66065987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30110 (or 30084 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 47.

The square root of 66065987 is about 8128.0986091459. The cubic root of 66065987 is about 404.2586386694.

The spelling of 66065987 in words is "sixty-six million, sixty-five thousand, nine hundred eighty-seven".