261324831444400 has 120 divisors (see below), whose sum is σ = 648371277872000. Its totient is φ = 101113405747200.

The previous prime is 261324831444367. The next prime is 261324831444401. The reversal of 261324831444400 is 4444138423162.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (261324831444401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23491576 + ... + 32779624.

Almost surely, 2^{261324831444400} is an apocalyptic number.

261324831444400 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 261324831444400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324185638936000).

261324831444400 is an abundant number, since it is smaller than the sum of its proper divisors (387046446427600).

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

261324831444400 is a wasteful number, since it uses less digits than its factorization.

261324831444400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9290367 (or 9290356 counting only the distinct ones).

The product of its (nonzero) digits is 1769472, while the sum is 46.

Adding to 261324831444400 its reverse (4444138423162), we get a palindrome (265768969867562).

The spelling of 261324831444400 in words is "two hundred sixty-one trillion, three hundred twenty-four billion, eight hundred thirty-one million, four hundred forty-four thousand, four hundred".