66120919 has 4 divisors (see below), whose sum is σ = 66143896. Its totient is φ = 66097944.

The previous prime is 66120911. The next prime is 66120947. The reversal of 66120919 is 91902166.

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 66120919 - 2³ = 66120911 is a prime.

It is a super-2 number, since 2×66120919² = 8743951858809122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66120911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6429 + ... + 13174.

It is an arithmetic number, because the mean of its divisors is an integer number (16535974).

Almost surely, 2^66120919 is an apocalyptic number.

66120919 is a deficient number, since it is larger than the sum of its proper divisors (22977).

66120919 is a wasteful number, since it uses less digits than its factorization.

66120919 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22976.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 66120919 is about 8131.4770490975. The cubic root of 66120919 is about 404.3706508391.

The spelling of 66120919 in words is "sixty-six million, one hundred twenty thousand, nine hundred nineteen".