261890512 has 60 divisors (see below), whose sum is σ = 573472224. Its totient is φ = 115589760.

The previous prime is 261890467. The next prime is 261890513. The reversal of 261890512 is 215098162.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261890513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 60087 + ... + 64297.

Almost surely, 2^261890512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261890512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (286736112).

261890512 is an abundant number, since it is smaller than the sum of its proper divisors (311581712).

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

261890512 is a wasteful number, since it uses less digits than its factorization.

261890512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4268 (or 4249 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 261890512 is about 16183.0316072113. The cubic root of 261890512 is about 639.7936444093.

The spelling of 261890512 in words is "two hundred sixty-one million, eight hundred ninety thousand, five hundred twelve".