261258720 has 192 divisors, whose sum is σ = 882778176. Its totient is φ = 64716800.

The previous prime is 261258719. The next prime is 261258743. The reversal of 261258720 is 27852162.

It is a super-2 number, since 2×261258720² = 136512237552076800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 824002 + ... + 824318.

It is an arithmetic number, because the mean of its divisors is an integer number (4597803).

Almost surely, 2^261258720 is an apocalyptic number.

261258720 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 261258720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (441389088).

261258720 is an abundant number, since it is smaller than the sum of its proper divisors (621519456).

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

261258720 is a wasteful number, since it uses less digits than its factorization.

261258720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 453 (or 445 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 261258720 is about 16163.4996210598. The cubic root of 261258720 is about 639.2787447703.

The spelling of 261258720 in words is "two hundred sixty-one million, two hundred fifty-eight thousand, seven hundred twenty".