1981879 has 2 divisors, whose sum is σ = 1981880. Its totient is φ = 1981878.

The previous prime is 1981867. The next prime is 1981883. The reversal of 1981879 is 9781891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1981879 - 2¹³ = 1973687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1982879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 990939 + 990940.

It is an arithmetic number, because the mean of its divisors is an integer number (990940).

2^1981879 is an apocalyptic number.

1981879 is a deficient number, since it is larger than the sum of its proper divisors (1).

1981879 is an equidigital number, since it uses as much as digits as its factorization.

1981879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 43.

The square root of 1981879 is about 1407.7922431950. The cubic root of 1981879 is about 125.6104327886.

The spelling of 1981879 in words is "one million, nine hundred eighty-one thousand, eight hundred seventy-nine".