2291987 has 2 divisors, whose sum is σ = 2291988. Its totient is φ = 2291986.

The previous prime is 2291983. The next prime is 2291999. The reversal of 2291987 is 7891922.

2291987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2291987 - 2² = 2291983 is a prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 2291987.

It is not a weakly prime, because it can be changed into another prime (2291983) 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, 1145993 + 1145994.

It is an arithmetic number, because the mean of its divisors is an integer number (1145994).

2^2291987 is an apocalyptic number.

2291987 is a deficient number, since it is larger than the sum of its proper divisors (1).

2291987 is an equidigital number, since it uses as much as digits as its factorization.

2291987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 38.

The square root of 2291987 is about 1513.9309759695. The cubic root of 2291987 is about 131.8471409297.

The spelling of 2291987 in words is "two million, two hundred ninety-one thousand, nine hundred eighty-seven".