2491957 has 4 divisors (see below), whose sum is σ = 2683660. Its totient is φ = 2300256.

The previous prime is 2491949. The next prime is 2491961. The reversal of 2491957 is 7591942.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 617796 + 1874161 = 786^2 + 1369^2 .

It is a cyclic number.

It is not a de Polignac number, because 2491957 - 2³ = 2491949 is a prime.

It is a Duffinian number.

2491957 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2491967) 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, 95832 + ... + 95857.

It is an arithmetic number, because the mean of its divisors is an integer number (670915).

2^2491957 is an apocalyptic number.

It is an amenable number.

2491957 is a deficient number, since it is larger than the sum of its proper divisors (191703).

2491957 is a wasteful number, since it uses less digits than its factorization.

2491957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191702.

The product of its digits is 22680, while the sum is 37.

The square root of 2491957 is about 1578.5933611922. The cubic root of 2491957 is about 135.5751773929.

It can be divided in two parts, 24919 and 57, that added together give a triangular number (24976 = T₂₂₃).

The spelling of 2491957 in words is "two million, four hundred ninety-one thousand, nine hundred fifty-seven".