261969872 has 20 divisors (see below), whose sum is σ = 534281280. Its totient is φ = 124090848.

The previous prime is 261969857. The next prime is 261969899. The reversal of 261969872 is 278969162.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 261969872.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 430568 + ... + 431175.

It is an arithmetic number, because the mean of its divisors is an integer number (26714064).

Almost surely, 2^261969872 is an apocalyptic number.

It is an amenable number.

261969872 is an abundant number, since it is smaller than the sum of its proper divisors (272311408).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261969872 is a wasteful number, since it uses less digits than its factorization.

261969872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 861770 (or 861764 counting only the distinct ones).

The product of its digits is 653184, while the sum is 50.

The square root of 261969872 is about 16185.4833724545. The cubic root of 261969872 is about 639.8582628834.

The spelling of 261969872 in words is "two hundred sixty-one million, nine hundred sixty-nine thousand, eight hundred seventy-two".