261545120 has 24 divisors (see below), whose sum is σ = 617900724. Its totient is φ = 104617984.

The previous prime is 261545071. The next prime is 261545143. The reversal of 261545120 is 21545162.

It can be written as a sum of positive squares in 2 ways, for example, as 256896784 + 4648336 = 16028^2 + 2156^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 261545120.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 817169 + ... + 817488.

Almost surely, 2^261545120 is an apocalyptic number.

261545120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261545120 is an abundant number, since it is smaller than the sum of its proper divisors (356355604).

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

261545120 is a wasteful number, since it uses less digits than its factorization.

261545120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1634672 (or 1634664 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 261545120 is about 16172.3566619092. The cubic root of 261545120 is about 639.5122585970.

The spelling of 261545120 in words is "two hundred sixty-one million, five hundred forty-five thousand, one hundred twenty".