261039209760 has 384 divisors, whose sum is σ = 1056747202560. Its totient is φ = 58946669568.

The previous prime is 261039209759. The next prime is 261039209779. The reversal of 261039209760 is 67902930162.

It is a happy number.

261039209760 is a `hidden beast` number, since 2 + 610 + 3 + 9 + 20 + 9 + 7 + 6 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2457919 + ... + 2561921.

It is an arithmetic number, because the mean of its divisors is an integer number (2751945840).

Almost surely, 2^261039209760 is an apocalyptic number.

261039209760 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 261039209760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (528373601280).

261039209760 is an abundant number, since it is smaller than the sum of its proper divisors (795707992800).

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

261039209760 is a wasteful number, since it uses less digits than its factorization.

261039209760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104117 (or 104103 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 45.

The spelling of 261039209760 in words is "two hundred sixty-one billion, thirty-nine million, two hundred nine thousand, seven hundred sixty".