261949163 has 32 divisors (see below), whose sum is σ = 321699840. Its totient is φ = 208565280.

The previous prime is 261949157. The next prime is 261949183. The reversal of 261949163 is 361949162.

It is not a de Polignac number, because 261949163 - 2¹⁴ = 261932779 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261949163.

It is not an unprimeable number, because it can be changed into a prime (261949133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 624968 + ... + 625386.

It is an arithmetic number, because the mean of its divisors is an integer number (10053120).

Almost surely, 2^261949163 is an apocalyptic number.

261949163 is a deficient number, since it is larger than the sum of its proper divisors (59750677).

261949163 is a wasteful number, since it uses less digits than its factorization.

261949163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 567.

The product of its digits is 69984, while the sum is 41.

The square root of 261949163 is about 16184.8436198809. The cubic root of 261949163 is about 639.8414019446.

Subtracting 261949163 from its reverse (361949162), we obtain a palindrome (99999999).

The spelling of 261949163 in words is "two hundred sixty-one million, nine hundred forty-nine thousand, one hundred sixty-three".