2123881 has 2 divisors, whose sum is σ = 2123882. Its totient is φ = 2123880.

The previous prime is 2123879. The next prime is 2123897. The reversal of 2123881 is 1883212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1155625 + 968256 = 1075^2 + 984^2 .

It is a cyclic number.

It is not a de Polignac number, because 2123881 - 2¹ = 2123879 is a prime.

It is a super-2 number, since 2×2123881² = 9021741004322, which contains 22 as substring.

Together with 2123879, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2123831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1061940 + 1061941.

It is an arithmetic number, because the mean of its divisors is an integer number (1061941).

2^2123881 is an apocalyptic number.

It is an amenable number.

2123881 is a deficient number, since it is larger than the sum of its proper divisors (1).

2123881 is an equidigital number, since it uses as much as digits as its factorization.

2123881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 768, while the sum is 25.

The square root of 2123881 is about 1457.3541093365. The cubic root of 2123881 is about 128.5415087934.

It can be divided in two parts, 21 and 23881, that multiplied together give a triangular number (501501 = T₁₀₀₁).

The spelling of 2123881 in words is "two million, one hundred twenty-three thousand, eight hundred eighty-one".