261885624 has 192 divisors, whose sum is σ = 886609920. Its totient is φ = 62726400.

The previous prime is 261885583. The next prime is 261885641. The reversal of 261885624 is 426588162.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 263769 + ... + 264759.

It is an arithmetic number, because the mean of its divisors is an integer number (4617760).

Almost surely, 2^261885624 is an apocalyptic number.

261885624 is a gapful number since it is divisible by the number (24) 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 261885624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (443304960).

261885624 is an abundant number, since it is smaller than the sum of its proper divisors (624724296).

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

261885624 is a wasteful number, since it uses less digits than its factorization.

261885624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1042 (or 1027 counting only the distinct ones).

The product of its digits is 184320, while the sum is 42.

The square root of 261885624 is about 16182.8805841235. The cubic root of 261885624 is about 639.7896639535.

The spelling of 261885624 in words is "two hundred sixty-one million, eight hundred eighty-five thousand, six hundred twenty-four".