66993261 has 8 divisors (see below), whose sum is σ = 90838560. Its totient is φ = 43905072.

The previous prime is 66993247. The next prime is 66993271. The reversal of 66993261 is 16239966.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66993261 - 2⁹ = 66992749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66993271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 189070 + ... + 189423.

It is an arithmetic number, because the mean of its divisors is an integer number (11354820).

Almost surely, 2^66993261 is an apocalyptic number.

It is an amenable number.

66993261 is a deficient number, since it is larger than the sum of its proper divisors (23845299).

66993261 is a wasteful number, since it uses less digits than its factorization.

66993261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 378555.

The product of its digits is 104976, while the sum is 42.

The square root of 66993261 is about 8184.9411115780. The cubic root of 66993261 is about 406.1411922882.

The spelling of 66993261 in words is "sixty-six million, nine hundred ninety-three thousand, two hundred sixty-one".