66938243 has 2 divisors, whose sum is σ = 66938244. Its totient is φ = 66938242.

The previous prime is 66938239. The next prime is 66938251. The reversal of 66938243 is 34283966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66938243 - 2² = 66938239 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66938243.

It is not a weakly prime, because it can be changed into another prime (66938213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33469121 + 33469122.

It is an arithmetic number, because the mean of its divisors is an integer number (33469122).

Almost surely, 2^66938243 is an apocalyptic number.

66938243 is a deficient number, since it is larger than the sum of its proper divisors (1).

66938243 is an equidigital number, since it uses as much as digits as its factorization.

66938243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 186624, while the sum is 41.

The square root of 66938243 is about 8181.5794929830. The cubic root of 66938243 is about 406.0299811230.

The spelling of 66938243 in words is "sixty-six million, nine hundred thirty-eight thousand, two hundred forty-three".