261311140860 has 768 divisors, whose sum is σ = 1041750097920. Its totient is φ = 47222784000.

The previous prime is 261311140817. The next prime is 261311140861. The reversal of 261311140860 is 68041113162.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261311140861) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 61180525 + ... + 61184795.

It is an arithmetic number, because the mean of its divisors is an integer number (1356445440).

Almost surely, 2^261311140860 is an apocalyptic number.

261311140860 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 261311140860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (520875048960).

261311140860 is an abundant number, since it is smaller than the sum of its proper divisors (780438957060).

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

261311140860 is a wasteful number, since it uses less digits than its factorization.

261311140860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4378 (or 4376 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The spelling of 261311140860 in words is "two hundred sixty-one billion, three hundred eleven million, one hundred forty thousand, eight hundred sixty".