491251131 has 24 divisors (see below), whose sum is σ = 814136544. Its totient is φ = 279613440.

The previous prime is 491251129. The next prime is 491251133. The reversal of 491251131 is 131152194.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (491251129) and next prime (491251133).

It is not a de Polignac number, because 491251131 - 2¹ = 491251129 is a prime.

It is a super-2 number, since 2×491251131² = 482655347417558322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 491251095 and 491251104.

It is not an unprimeable number, because it can be changed into a prime (491251133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1021 + ... + 31361.

It is an arithmetic number, because the mean of its divisors is an integer number (33922356).

Almost surely, 2^491251131 is an apocalyptic number.

491251131 is a deficient number, since it is larger than the sum of its proper divisors (322885413).

491251131 is a wasteful number, since it uses less digits than its factorization.

491251131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30611 (or 30608 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 491251131 is about 22164.1857734499. The cubic root of 491251131 is about 789.0439382394.

The spelling of 491251131 in words is "four hundred ninety-one million, two hundred fifty-one thousand, one hundred thirty-one".