66797918 has 8 divisors (see below), whose sum is σ = 109305720. Its totient is φ = 30362680.

The previous prime is 66797917. The next prime is 66797953. The reversal of 66797918 is 81979766.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 66797918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66797917) 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, 1518113 + ... + 1518156.

It is an arithmetic number, because the mean of its divisors is an integer number (13663215).

Almost surely, 2^66797918 is an apocalyptic number.

66797918 is a deficient number, since it is larger than the sum of its proper divisors (42507802).

66797918 is a wasteful number, since it uses less digits than its factorization.

66797918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3036282.

The product of its digits is 1143072, while the sum is 53.

The square root of 66797918 is about 8172.9993270525. Note that the first 3 decimals coincide. The cubic root of 66797918 is about 405.7460576402.

The spelling of 66797918 in words is "sixty-six million, seven hundred ninety-seven thousand, nine hundred eighteen".