261013491 has 6 divisors (see below), whose sum is σ = 377019500. Its totient is φ = 174008988.

The previous prime is 261013481. The next prime is 261013523. The reversal of 261013491 is 194310162.

261013491 is a `hidden beast` number, since 2 + 610 + 1 + 3 + 49 + 1 = 666.

It is not a de Polignac number, because 261013491 - 2⁹ = 261012979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261013411) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 14500741 + ... + 14500758.

Almost surely, 2^261013491 is an apocalyptic number.

261013491 is a deficient number, since it is larger than the sum of its proper divisors (116006009).

261013491 is a wasteful number, since it uses less digits than its factorization.

261013491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29001505 (or 29001502 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 261013491 is about 16155.9119519760. The cubic root of 261013491 is about 639.0786637124.

It can be divided in two parts, 26101 and 3491, that added together give a palindrome (29592).

The spelling of 261013491 in words is "two hundred sixty-one million, thirteen thousand, four hundred ninety-one".