261129456 has 120 divisors (see below), whose sum is σ = 864096480. Its totient is φ = 72027648.

The previous prime is 261129443. The next prime is 261129481. The reversal of 261129456 is 654921162.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 261129456.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24766 + ... + 33698.

It is an arithmetic number, because the mean of its divisors is an integer number (7200804).

Almost surely, 2^261129456 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 261129456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (432048240).

261129456 is an abundant number, since it is smaller than the sum of its proper divisors (602967024).

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

261129456 is a wasteful number, since it uses less digits than its factorization.

261129456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8983 (or 8974 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 261129456 is about 16159.5004873294. The cubic root of 261129456 is about 639.1732945610.

The spelling of 261129456 in words is "two hundred sixty-one million, one hundred twenty-nine thousand, four hundred fifty-six".