261251760 has 320 divisors, whose sum is σ = 1029648384. Its totient is φ = 53222400.

The previous prime is 261251741. The next prime is 261251761. The reversal of 261251760 is 67152162.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (261251761) 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 63 ways as a sum of consecutive naturals, for example, 1238055 + ... + 1238265.

Almost surely, 2^261251760 is an apocalyptic number.

261251760 is a gapful number since it is divisible by the number (20) 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 261251760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (514824192).

261251760 is an abundant number, since it is smaller than the sum of its proper divisors (768396624).

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

261251760 is a wasteful number, since it uses less digits than its factorization.

261251760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312 (or 306 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 261251760 is about 16163.2843197167. The cubic root of 261251760 is about 639.2730678694.

The spelling of 261251760 in words is "two hundred sixty-one million, two hundred fifty-one thousand, seven hundred sixty".