2491257 has 4 divisors (see below), whose sum is σ = 3321680. Its totient is φ = 1660836.

The previous prime is 2491243. The next prime is 2491259. The reversal of 2491257 is 7521942.

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 not a de Polignac number, because 2491257 - 2⁸ = 2491001 is a prime.

It is a super-2 number, since 2×2491257² = 12412722880098, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

2491257 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2491259) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 415207 + ... + 415212.

It is an arithmetic number, because the mean of its divisors is an integer number (830420).

2^2491257 is an apocalyptic number.

It is an amenable number.

2491257 is a deficient number, since it is larger than the sum of its proper divisors (830423).

2491257 is an equidigital number, since it uses as much as digits as its factorization.

2491257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 830422.

The product of its digits is 5040, while the sum is 30.

The square root of 2491257 is about 1578.3716292433. The cubic root of 2491257 is about 135.5624816800.

The spelling of 2491257 in words is "two million, four hundred ninety-one thousand, two hundred fifty-seven".