1211181804 has 54 divisors (see below), whose sum is σ = 3561456444. Its totient is φ = 346051440.

The previous prime is 1211181793. The next prime is 1211181821. The reversal of 1211181804 is 4081811121.

It is a super-2 number, since 2×1211181804² = 2933922724681388832, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 341542 + ... + 345069.

Almost surely, 2^1211181804 is an apocalyptic number.

1211181804 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1211181804 is an abundant number, since it is smaller than the sum of its proper divisors (2350274640).

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

1211181804 is a wasteful number, since it uses less digits than its factorization.

1211181804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686635 (or 686623 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 27.

The square root of 1211181804 is about 34802.0373541550. The cubic root of 1211181804 is about 1065.9490475689.

Adding to 1211181804 its reverse (4081811121), we get a palindrome (5292992925).

The spelling of 1211181804 in words is "one billion, two hundred eleven million, one hundred eighty-one thousand, eight hundred four".