66961199 has 4 divisors (see below), whose sum is σ = 66990000. Its totient is φ = 66932400.

The previous prime is 66961183. The next prime is 66961217. The reversal of 66961199 is 99116966.

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 66961199 - 2⁴ = 66961183 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 (66961129) 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, 10574 + ... + 15675.

It is an arithmetic number, because the mean of its divisors is an integer number (16747500).

Almost surely, 2^66961199 is an apocalyptic number.

66961199 is a deficient number, since it is larger than the sum of its proper divisors (28801).

66961199 is a wasteful number, since it uses less digits than its factorization.

66961199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28800.

The product of its digits is 157464, while the sum is 47.

The square root of 66961199 is about 8182.9822803181. The cubic root of 66961199 is about 406.0763908609.

The spelling of 66961199 in words is "sixty-six million, nine hundred sixty-one thousand, one hundred ninety-nine".