491038261 has 24 divisors (see below), whose sum is σ = 606151680. Its totient is φ = 395502912.

The previous prime is 491038253. The next prime is 491038279. The reversal of 491038261 is 162830194.

It is not a de Polignac number, because 491038261 - 2³ = 491038253 is a prime.

It is a super-2 number, since 2×491038261² = 482237147531808242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491038231) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 116161 + ... + 120313.

It is an arithmetic number, because the mean of its divisors is an integer number (25256320).

Almost surely, 2^491038261 is an apocalyptic number.

It is an amenable number.

491038261 is a deficient number, since it is larger than the sum of its proper divisors (115113419).

491038261 is a wasteful number, since it uses less digits than its factorization.

491038261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4313 (or 4306 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 491038261 is about 22159.3831367211. The cubic root of 491038261 is about 788.9299516996.

The spelling of 491038261 in words is "four hundred ninety-one million, thirty-eight thousand, two hundred sixty-one".