66931798 has 4 divisors (see below), whose sum is σ = 100397700. Its totient is φ = 33465898.

The previous prime is 66931793. The next prime is 66931829. The reversal of 66931798 is 89713966.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 89713966 = 2 ⋅44856983.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66931793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16732948 + ... + 16732951.

It is an arithmetic number, because the mean of its divisors is an integer number (25099425).

Almost surely, 2^66931798 is an apocalyptic number.

66931798 is a deficient number, since it is larger than the sum of its proper divisors (33465902).

66931798 is a wasteful number, since it uses less digits than its factorization.

66931798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33465901.

The product of its digits is 489888, while the sum is 49.

The square root of 66931798 is about 8181.1856109002. The cubic root of 66931798 is about 406.0169494732.

The spelling of 66931798 in words is "sixty-six million, nine hundred thirty-one thousand, seven hundred ninety-eight".