261351520 has 24 divisors (see below), whose sum is σ = 617443344. Its totient is φ = 104540544.

The previous prime is 261351481. The next prime is 261351521. The reversal of 261351520 is 25153162.

261351520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261351521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 816564 + ... + 816883.

It is an arithmetic number, because the mean of its divisors is an integer number (25726806).

Almost surely, 2^261351520 is an apocalyptic number.

261351520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261351520 is an abundant number, since it is smaller than the sum of its proper divisors (356091824).

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

261351520 is a wasteful number, since it uses less digits than its factorization.

261351520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1633462 (or 1633454 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 261351520 is about 16166.3700316428. The cubic root of 261351520 is about 639.3544271497.

The spelling of 261351520 in words is "two hundred sixty-one million, three hundred fifty-one thousand, five hundred twenty".