1881181 has 2 divisors, whose sum is σ = 1881182. Its totient is φ = 1881180.

The previous prime is 1881163. The next prime is 1881197. The reversal of 1881181 is 1811881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1863225 + 17956 = 1365^2 + 134^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1881181 is a prime.

It is a super-2 number, since 2×1881181² = 7077683909522, which contains 22 as substring.

1881181 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1881151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 940590 + 940591.

It is an arithmetic number, because the mean of its divisors is an integer number (940591).

2^1881181 is an apocalyptic number.

It is an amenable number.

1881181 is a deficient number, since it is larger than the sum of its proper divisors (1).

1881181 is an equidigital number, since it uses as much as digits as its factorization.

1881181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 512, while the sum is 28.

The square root of 1881181 is about 1371.5615188536. The cubic root of 1881181 is about 123.4459542679.

It can be divided in two parts, 188 and 1181, that added together give a square (1369 = 37²).

The spelling of 1881181 in words is "one million, eight hundred eighty-one thousand, one hundred eighty-one".