261541341520 has 40 divisors (see below), whose sum is σ = 608113265760. Its totient is φ = 104611436160.

The previous prime is 261541341517. The next prime is 261541341563. The reversal of 261541341520 is 25143145162.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1866715 + ... + 2001925.

It is an arithmetic number, because the mean of its divisors is an integer number (15202831644).

Almost surely, 2^261541341520 is an apocalyptic number.

261541341520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261541341520 is an abundant number, since it is smaller than the sum of its proper divisors (346571924240).

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

261541341520 is a wasteful number, since it uses less digits than its factorization.

261541341520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159403 (or 159397 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 34.

Adding to 261541341520 its reverse (25143145162), we get a palindrome (286684486682).

The spelling of 261541341520 in words is "two hundred sixty-one billion, five hundred forty-one million, three hundred forty-one thousand, five hundred twenty".