1191012818 has 18 divisors (see below), whose sum is σ = 1869332997. Its totient is φ = 569077960.

The previous prime is 1191012817. The next prime is 1191012829. The reversal of 1191012818 is 8182101911.

It can be written as a sum of positive squares in 2 ways, for example, as 1160287969 + 30724849 = 34063^2 + 5543^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=24403.

It is a super-2 number, since 2×1191012818² = 2837023065280602248, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1191012817) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1122008 + ... + 1123068.

Almost surely, 2^1191012818 is an apocalyptic number.

1191012818 is a deficient number, since it is larger than the sum of its proper divisors (678320179).

1191012818 is an frugal number, since it uses more digits than its factorization.

1191012818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2170 (or 1086 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 32.

The square root of 1191012818 is about 34511.0535625906. The cubic root of 1191012818 is about 1059.9990560096. Note that the first 3 decimals are identical.

Multiplying 1191012818 by its sum of digits (32), we get a square (38112410176 = 195224²).

Multiplying 1191012818 by its product of nonzero digits (1152), we get a square (1372046766336 = 1171344²).

The spelling of 1191012818 in words is "one billion, one hundred ninety-one million, twelve thousand, eight hundred eighteen".