66983687 has 4 divisors (see below), whose sum is σ = 67056720. Its totient is φ = 66910656.

The previous prime is 66983677. The next prime is 66983701. The reversal of 66983687 is 78638966.

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 66983687 - 2²² = 62789383 is a prime.

It is a super-2 number, since 2×66983687² = 8973628648227938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66983647) 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, 35123 + ... + 36980.

It is an arithmetic number, because the mean of its divisors is an integer number (16764180).

Almost surely, 2^66983687 is an apocalyptic number.

66983687 is a deficient number, since it is larger than the sum of its proper divisors (73033).

66983687 is an equidigital number, since it uses as much as digits as its factorization.

66983687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73032.

The product of its digits is 2612736, while the sum is 53.

The square root of 66983687 is about 8184.3562361373. The cubic root of 66983687 is about 406.1218441679.

The spelling of 66983687 in words is "sixty-six million, nine hundred eighty-three thousand, six hundred eighty-seven".