261564263025600 has 336 divisors, whose sum is σ = 860087883852288. Its totient is φ = 69592933724160.

The previous prime is 261564263025587. The next prime is 261564263025607. The reversal of 261564263025600 is 6520362465162.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 261564263025600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261564263025607) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10447096282 + ... + 10447121318.

It is an arithmetic number, because the mean of its divisors is an integer number (2559785368608).

Almost surely, 2^{261564263025600} is an apocalyptic number.

261564263025600 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 261564263025600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (430043941926144).

261564263025600 is an abundant number, since it is smaller than the sum of its proper divisors (598523620826688).

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

261564263025600 is a wasteful number, since it uses less digits than its factorization.

261564263025600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29892 (or 29877 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 48.

The spelling of 261564263025600 in words is "two hundred sixty-one trillion, five hundred sixty-four billion, two hundred sixty-three million, twenty-five thousand, six hundred".