66237791 has 4 divisors (see below), whose sum is σ = 67145232. Its totient is φ = 65330352.

The previous prime is 66237779. The next prime is 66237799. The reversal of 66237791 is 19773266.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19773266 = 2 ⋅9886633.

It is a cyclic number.

It is not a de Polignac number, because 66237791 - 2⁶ = 66237727 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66237799) 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, 453611 + ... + 453756.

It is an arithmetic number, because the mean of its divisors is an integer number (16786308).

Almost surely, 2^66237791 is an apocalyptic number.

66237791 is a deficient number, since it is larger than the sum of its proper divisors (907441).

66237791 is an equidigital number, since it uses as much as digits as its factorization.

66237791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 907440.

The product of its digits is 95256, while the sum is 41.

The square root of 66237791 is about 8138.6602705851. The cubic root of 66237791 is about 404.6087589908.

The spelling of 66237791 in words is "sixty-six million, two hundred thirty-seven thousand, seven hundred ninety-one".