66868155 has 24 divisors (see below), whose sum is σ = 117542880. Its totient is φ = 35159040.

The previous prime is 66868129. The next prime is 66868159. The reversal of 66868155 is 55186866.

It is not a de Polignac number, because 66868155 - 2⁶ = 66868091 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 66868155.

It is not an unprimeable number, because it can be changed into a prime (66868159) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7270 + ... + 13659.

It is an arithmetic number, because the mean of its divisors is an integer number (4897620).

Almost surely, 2^66868155 is an apocalyptic number.

66868155 is a deficient number, since it is larger than the sum of its proper divisors (50674725).

66868155 is a wasteful number, since it uses less digits than its factorization.

66868155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21011 (or 21008 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The square root of 66868155 is about 8177.2950906764. The cubic root of 66868155 is about 405.8882197714. Note that the first 3 decimals are identical.

It can be divided in two parts, 6686 and 8155, that added together give a palindrome (14841).

The spelling of 66868155 in words is "sixty-six million, eight hundred sixty-eight thousand, one hundred fifty-five".