261986928 has 240 divisors, whose sum is σ = 854945280. Its totient is φ = 68716032.

The previous prime is 261986911. The next prime is 261986929. The reversal of 261986928 is 829689162.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261986929) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1568701 + ... + 1568867.

It is an arithmetic number, because the mean of its divisors is an integer number (3562272).

Almost surely, 2^261986928 is an apocalyptic number.

261986928 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261986928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (427472640).

261986928 is an abundant number, since it is smaller than the sum of its proper divisors (592958352).

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

261986928 is a wasteful number, since it uses less digits than its factorization.

261986928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244 (or 231 counting only the distinct ones).

The product of its digits is 746496, while the sum is 51.

The square root of 261986928 is about 16186.0102557733. The cubic root of 261986928 is about 639.8721489404.

The spelling of 261986928 in words is "two hundred sixty-one million, nine hundred eighty-six thousand, nine hundred twenty-eight".