66998684 has 12 divisors (see below), whose sum is σ = 117752544. Its totient is φ = 33355104.

The previous prime is 66998647. The next prime is 66998707. The reversal of 66998684 is 48689966.

66998684 = 416² + 417² + ... + 648².

It is a super-3 number, since 3×66998684³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35012 + ... + 36875.

It is an arithmetic number, because the mean of its divisors is an integer number (9812712).

Almost surely, 2^66998684 is an apocalyptic number.

It is an amenable number.

66998684 is a deficient number, since it is larger than the sum of its proper divisors (50753860).

66998684 is a wasteful number, since it uses less digits than its factorization.

66998684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72124 (or 72122 counting only the distinct ones).

The product of its digits is 4478976, while the sum is 56.

The square root of 66998684 is about 8185.2723839833. The cubic root of 66998684 is about 406.1521508245.

The spelling of 66998684 in words is "sixty-six million, nine hundred ninety-eight thousand, six hundred eighty-four".