261888547442400 has 288 divisors, whose sum is σ = 947181021534720. Its totient is φ = 69835659978240.

The previous prime is 261888547442387. The next prime is 261888547442407. The reversal of 261888547442400 is 4244745888162.

261888547442400 is a `hidden beast` number, since 2 + 6 + 1 + 8 + 8 + 8 + 547 + 4 + 42 + 40 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×261888547442400² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261888547442407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2014415799 + ... + 2014545801.

It is an arithmetic number, because the mean of its divisors is an integer number (3288822991440).

Almost surely, 2^{261888547442400} is an apocalyptic number.

261888547442400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261888547442400 is an abundant number, since it is smaller than the sum of its proper divisors (685292474092320).

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

261888547442400 is a wasteful number, since it uses less digits than its factorization.

261888547442400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223295 (or 223276 counting only the distinct ones).

The product of its (nonzero) digits is 110100480, while the sum is 63.

The spelling of 261888547442400 in words is "two hundred sixty-one trillion, eight hundred eighty-eight billion, five hundred forty-seven million, four hundred forty-two thousand, four hundred".