66039986 has 4 divisors (see below), whose sum is σ = 99059982. Its totient is φ = 33019992.

The previous prime is 66039979. The next prime is 66039997. The reversal of 66039986 is 68993066.

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

It can be written as a sum of positive squares in only one way, i.e., 65108761 + 931225 = 8069^2 + 965^2 .

It is a super-2 number, since 2×66039986² = 8722559501760392, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66039986.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16509995 + ... + 16509998.

Almost surely, 2^66039986 is an apocalyptic number.

66039986 is a deficient number, since it is larger than the sum of its proper divisors (33019996).

66039986 is a wasteful number, since it uses less digits than its factorization.

66039986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33019995.

The product of its (nonzero) digits is 419904, while the sum is 47.

The square root of 66039986 is about 8126.4990001845. The cubic root of 66039986 is about 404.2055982242.

The spelling of 66039986 in words is "sixty-six million, thirty-nine thousand, nine hundred eighty-six".