1881138121 has 2 divisors, whose sum is σ = 1881138122. Its totient is φ = 1881138120.

The previous prime is 1881138109. The next prime is 1881138137. The reversal of 1881138121 is 1218311881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1809566521 + 71571600 = 42539^2 + 8460^2 .

It is a cyclic number.

It is not a de Polignac number, because 1881138121 - 2⁵ = 1881138089 is a prime.

It is not a weakly prime, because it can be changed into another prime (1881138151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 940569060 + 940569061.

It is an arithmetic number, because the mean of its divisors is an integer number (940569061).

Almost surely, 2^1881138121 is an apocalyptic number.

It is an amenable number.

1881138121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1881138121 is an equidigital number, since it uses as much as digits as its factorization.

1881138121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3072, while the sum is 34.

The square root of 1881138121 is about 43372.0891933972. The cubic root of 1881138121 is about 1234.4501633244.

The spelling of 1881138121 in words is "one billion, eight hundred eighty-one million, one hundred thirty-eight thousand, one hundred twenty-one".