1916881 has 2 divisors, whose sum is σ = 1916882. Its totient is φ = 1916880.

The previous prime is 1916867. The next prime is 1916909. The reversal of 1916881 is 1886191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1404225 + 512656 = 1185^2 + 716^2 .

It is a cyclic number.

It is not a de Polignac number, because 1916881 - 2⁷ = 1916753 is a prime.

It is a super-2 number, since 2×1916881² = 7348865536322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1916281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 958440 + 958441.

It is an arithmetic number, because the mean of its divisors is an integer number (958441).

2^1916881 is an apocalyptic number.

It is an amenable number.

1916881 is a deficient number, since it is larger than the sum of its proper divisors (1).

1916881 is an equidigital number, since it uses as much as digits as its factorization.

1916881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 34.

The square root of 1916881 is about 1384.5147164259. The cubic root of 1916881 is about 124.2219619688.

It can be divided in two parts, 19 and 16881, that added together give a square (16900 = 130²).

The spelling of 1916881 in words is "one million, nine hundred sixteen thousand, eight hundred eighty-one".