4491989 has 2 divisors, whose sum is σ = 4491990. Its totient is φ = 4491988.

The previous prime is 4491953. The next prime is 4491997. The reversal of 4491989 is 9891944.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3783025 + 708964 = 1945^2 + 842^2 .

It is a cyclic number.

It is not a de Polignac number, because 4491989 - 2²⁰ = 3443413 is a prime.

It is a super-2 number, since 2×4491989² = 40355930352242, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4491089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2245994 + 2245995.

It is an arithmetic number, because the mean of its divisors is an integer number (2245995).

Almost surely, 2^4491989 is an apocalyptic number.

It is an amenable number.

4491989 is a deficient number, since it is larger than the sum of its proper divisors (1).

4491989 is an equidigital number, since it uses as much as digits as its factorization.

4491989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 44.

The square root of 4491989 is about 2119.4312916441. The cubic root of 4491989 is about 164.9983348470.

The spelling of 4491989 in words is "four million, four hundred ninety-one thousand, nine hundred eighty-nine".