261573400000 has 168 divisors, whose sum is σ = 707769356112. Its totient is φ = 95116800000.

The previous prime is 261573399991. The next prime is 261573400087. The reversal of 261573400000 is 4375162.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2140552 + ... + 2259448.

It is an arithmetic number, because the mean of its divisors is an integer number (4212912834).

Almost surely, 2^261573400000 is an apocalyptic number.

261573400000 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 261573400000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (353884678056).

261573400000 is an abundant number, since it is smaller than the sum of its proper divisors (446195956112).

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

261573400000 is an equidigital number, since it uses as much as digits as its factorization.

261573400000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118945 (or 118915 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 28.

Adding to 261573400000 its reverse (4375162), we get a palindrome (261577775162).

The spelling of 261573400000 in words is "two hundred sixty-one billion, five hundred seventy-three million, four hundred thousand".