261478451200 has 144 divisors (see below), whose sum is σ = 664125969780. Its totient is φ = 102039552000.

The previous prime is 261478451191. The next prime is 261478451203. The reversal of 261478451200 is 2154874162.

It can be written as a sum of positive squares in 6 ways, for example, as 22127616 + 261456323584 = 4704^2 + 511328^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (261478451203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2036920 + ... + 2161480.

Almost surely, 2^261478451200 is an apocalyptic number.

261478451200 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 261478451200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (332062984890).

261478451200 is an abundant number, since it is smaller than the sum of its proper divisors (402647518580).

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

261478451200 is a wasteful number, since it uses less digits than its factorization.

261478451200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124634 (or 124609 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 40.

The spelling of 261478451200 in words is "two hundred sixty-one billion, four hundred seventy-eight million, four hundred fifty-one thousand, two hundred".