1818156666 has 32 divisors (see below), whose sum is σ = 3712806720. Its totient is φ = 593433344.

The previous prime is 1818156661. The next prime is 1818156671. The reversal of 1818156666 is 6666518181.

It is an interprime number because it is at equal distance from previous prime (1818156661) and next prime (1818156671).

It is not an unprimeable number, because it can be changed into a prime (1818156661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40120 + ... + 72428.

It is an arithmetic number, because the mean of its divisors is an integer number (116025210).

Almost surely, 2^1818156666 is an apocalyptic number.

1818156666 is an abundant number, since it is smaller than the sum of its proper divisors (1894650054).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1818156666 is a wasteful number, since it uses less digits than its factorization.

1818156666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32510.

The product of its digits is 414720, while the sum is 48.

The square root of 1818156666 is about 42639.8483346271. The cubic root of 1818156666 is about 1220.5168163306.

It can be divided in two parts, 18181 and 56666, that added together give a palindrome (74847).

The spelling of 1818156666 in words is "one billion, eight hundred eighteen million, one hundred fifty-six thousand, six hundred sixty-six".