1881641 has 2 divisors, whose sum is σ = 1881642. Its totient is φ = 1881640.

The previous prime is 1881631. The next prime is 1881697. The reversal of 1881641 is 1461881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1849600 + 32041 = 1360^2 + 179^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1881641 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1881601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 940820 + 940821.

It is an arithmetic number, because the mean of its divisors is an integer number (940821).

2^1881641 is an apocalyptic number.

It is an amenable number.

1881641 is a deficient number, since it is larger than the sum of its proper divisors (1).

1881641 is an equidigital number, since it uses as much as digits as its factorization.

1881641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 29.

The square root of 1881641 is about 1371.7292006807. The cubic root of 1881641 is about 123.4560154141.

The spelling of 1881641 in words is "one million, eight hundred eighty-one thousand, six hundred forty-one".