261520500 has 48 divisors (see below), whose sum is σ = 761552064. Its totient is φ = 69738400.

The previous prime is 261520489. The next prime is 261520507. The reversal of 261520500 is 5025162.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261520507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85674 + ... + 88673.

It is an arithmetic number, because the mean of its divisors is an integer number (15865668).

Almost surely, 2^261520500 is an apocalyptic number.

261520500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261520500 is an abundant number, since it is smaller than the sum of its proper divisors (500031564).

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

261520500 is a wasteful number, since it uses less digits than its factorization.

261520500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174369 (or 174357 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 261520500 is about 16171.5954685986. The cubic root of 261520500 is about 639.4921915867.

Adding to 261520500 its reverse (5025162), we get a palindrome (266545662).

The spelling of 261520500 in words is "two hundred sixty-one million, five hundred twenty thousand, five hundred".