261847872 has 378 divisors, whose sum is σ = 943767734. Its totient is φ = 68935680.

The previous prime is 261847871. The next prime is 261847877. The reversal of 261847872 is 278748162.

It can be written as a sum of positive squares in 3 ways, for example, as 58614336 + 203233536 = 7656^2 + 14256^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261847871) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 15402808 + ... + 15402824.

Almost surely, 2^261847872 is an apocalyptic number.

261847872 is a gapful number since it is divisible by the number (22) 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 261847872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (471883867).

261847872 is an abundant number, since it is smaller than the sum of its proper divisors (681919862).

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

261847872 is a wasteful number, since it uses less digits than its factorization.

261847872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87 (or 46 counting only the distinct ones).

The product of its digits is 301056, while the sum is 45.

The square root of 261847872 is about 16181.7141242824. The cubic root of 261847872 is about 639.7589196160.

The spelling of 261847872 in words is "two hundred sixty-one million, eight hundred forty-seven thousand, eight hundred seventy-two".