2581989 has 4 divisors (see below), whose sum is σ = 3442656. Its totient is φ = 1721324.

The previous prime is 2581973. The next prime is 2581991. The reversal of 2581989 is 9891852.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2581989 - 2⁴ = 2581973 is a prime.

It is a super-2 number, since 2×2581989² = 13333334392242, which contains 22 as substring.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 2581989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2581919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 430329 + ... + 430334.

It is an arithmetic number, because the mean of its divisors is an integer number (860664).

2^2581989 is an apocalyptic number.

It is an amenable number.

2581989 is a deficient number, since it is larger than the sum of its proper divisors (860667).

2581989 is an equidigital number, since it uses as much as digits as its factorization.

2581989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 860666.

The product of its digits is 51840, while the sum is 42.

The square root of 2581989 is about 1606.8568697927. The cubic root of 2581989 is about 137.1886331875.

It can be divided in two parts, 2581 and 989, that added together give a triangular number (3570 = T₈₄).

The spelling of 2581989 in words is "two million, five hundred eighty-one thousand, nine hundred eighty-nine".