261635028 has 48 divisors (see below), whose sum is σ = 647861760. Its totient is φ = 82000864.

The previous prime is 261635021. The next prime is 261635089. The reversal of 261635028 is 820536162.

It is a self number, because there is not a number n which added to its sum of digits gives 261635028.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261635021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8251 + ... + 24317.

It is an arithmetic number, because the mean of its divisors is an integer number (13497120).

Almost surely, 2^261635028 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 261635028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (323930880).

261635028 is an abundant number, since it is smaller than the sum of its proper divisors (386226732).

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

261635028 is a wasteful number, since it uses less digits than its factorization.

261635028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16156 (or 16154 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 261635028 is about 16175.1361045278. The cubic root of 261635028 is about 639.5855291682.

The spelling of 261635028 in words is "two hundred sixty-one million, six hundred thirty-five thousand, twenty-eight".