261444636721460 has 96 divisors (see below), whose sum is σ = 572321213291520. Its totient is φ = 100197503078400.

The previous prime is 261444636721451. The next prime is 261444636721469. The reversal of 261444636721460 is 64127636444162.

It is an interprime number because it is at equal distance from previous prime (261444636721451) and next prime (261444636721469).

It is a junction number, because it is equal to n+sod(n) for n = 261444636721396 and 261444636721405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261444636721469) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3941125412 + ... + 3941191748.

It is an arithmetic number, because the mean of its divisors is an integer number (5961679305120).

Almost surely, 2^{261444636721460} is an apocalyptic number.

261444636721460 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261444636721460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (286160606645760).

261444636721460 is an abundant number, since it is smaller than the sum of its proper divisors (310876576570060).

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

261444636721460 is a wasteful number, since it uses less digits than its factorization.

261444636721460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118377 (or 118375 counting only the distinct ones).

The product of its (nonzero) digits is 27869184, while the sum is 56.

The spelling of 261444636721460 in words is "two hundred sixty-one trillion, four hundred forty-four billion, six hundred thirty-six million, seven hundred twenty-one thousand, four hundred sixty".