1211881 has 12 divisors (see below), whose sum is σ = 1379664. Its totient is φ = 1055600.

The previous prime is 1211863. The next prime is 1211897. The reversal of 1211881 is 1881121.

It is not a de Polignac number, because 1211881 - 2¹³ = 1203689 is a prime.

It is a super-2 number, since 2×1211881² = 2937311116322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1211081) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 9186 + ... + 9316.

It is an arithmetic number, because the mean of its divisors is an integer number (114972).

2^1211881 is an apocalyptic number.

1211881 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211881 is a deficient number, since it is larger than the sum of its proper divisors (167783).

1211881 is a wasteful number, since it uses less digits than its factorization.

1211881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200 (or 171 counting only the distinct ones).

The product of its digits is 128, while the sum is 22.

The square root of 1211881 is about 1100.8546679739. The cubic root of 1211881 is about 106.6154126591.

It can be divided in two parts, 121 and 1881, that added together give a palindrome (2002).

The spelling of 1211881 in words is "one million, two hundred eleven thousand, eight hundred eighty-one".