2581491 has 16 divisors (see below), whose sum is σ = 3788928. Its totient is φ = 1550400.

The previous prime is 2581487. The next prime is 2581507. The reversal of 2581491 is 1941852.

It is a happy number.

It is not a de Polignac number, because 2581491 - 2² = 2581487 is a prime.

2581491 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2581441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4236 + ... + 4806.

It is an arithmetic number, because the mean of its divisors is an integer number (236808).

2^2581491 is an apocalyptic number.

2581491 is a deficient number, since it is larger than the sum of its proper divisors (1207437).

2581491 is a wasteful number, since it uses less digits than its factorization.

2581491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 722.

The product of its digits is 2880, while the sum is 30.

The square root of 2581491 is about 1606.7019014117. The cubic root of 2581491 is about 137.1798125545.

The spelling of 2581491 in words is "two million, five hundred eighty-one thousand, four hundred ninety-one".