261345939712 has 288 divisors, whose sum is σ = 656881424640. Its totient is φ = 102041026560.

The previous prime is 261345939709. The next prime is 261345939713. The reversal of 261345939712 is 217939543162.

It is a Harshad number since it is a multiple of its sum of digits (52).

It is a self number, because there is not a number n which added to its sum of digits gives 261345939712.

It is not an unprimeable number, because it can be changed into a prime (261345939713) 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 31 ways as a sum of consecutive naturals, for example, 31149214 + ... + 31157602.

It is an arithmetic number, because the mean of its divisors is an integer number (2280838280).

Almost surely, 2^261345939712 is an apocalyptic number.

261345939712 is a gapful number since it is divisible by the number (22) 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 261345939712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (328440712320).

261345939712 is an abundant number, since it is smaller than the sum of its proper divisors (395535484928).

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

261345939712 is a wasteful number, since it uses less digits than its factorization.

261345939712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8489 (or 8475 counting only the distinct ones).

The product of its digits is 2449440, while the sum is 52.

The spelling of 261345939712 in words is "two hundred sixty-one billion, three hundred forty-five million, nine hundred thirty-nine thousand, seven hundred twelve".