261201582580 has 24 divisors (see below), whose sum is σ = 548557593192. Its totient is φ = 104474105472.

The previous prime is 261201582529. The next prime is 261201582601. The reversal of 261201582580 is 85285102162.

It can be written as a sum of positive squares in 4 ways, for example, as 8194594576 + 253006988004 = 90524^2 + 502998^2 .

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, 73147 + ... + 726466.

It is an arithmetic number, because the mean of its divisors is an integer number (22856566383).

Almost surely, 2^261201582580 is an apocalyptic number.

261201582580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261201582580 is an abundant number, since it is smaller than the sum of its proper divisors (287356010612).

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

261201582580 is a wasteful number, since it uses less digits than its factorization.

261201582580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815955 (or 815953 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 40.

It can be divided in two parts, 261201582 and 580, that added together give a palindrome (261202162).

The spelling of 261201582580 in words is "two hundred sixty-one billion, two hundred one million, five hundred eighty-two thousand, five hundred eighty".