261861252800 has 504 divisors, whose sum is σ = 792792115200. Its totient is φ = 84646840320.

The previous prime is 261861252761. The next prime is 261861252823. The reversal of 261861252800 is 8252168162.

It is a happy number.

261861252800 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 546682961 + ... + 546683439.

Almost surely, 2^261861252800 is an apocalyptic number.

261861252800 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 261861252800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (396396057600).

261861252800 is an abundant number, since it is smaller than the sum of its proper divisors (530930862400).

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

261861252800 is a wasteful number, since it uses less digits than its factorization.

261861252800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 901 (or 879 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 41.

The spelling of 261861252800 in words is "two hundred sixty-one billion, eight hundred sixty-one million, two hundred fifty-two thousand, eight hundred".