261647100 has 432 divisors, whose sum is σ = 1023684480. Its totient is φ = 54950400.

The previous prime is 261647063. The next prime is 261647101. The reversal of 261647100 is 1746162.

261647100 is a `hidden beast` number, since 2 + 6 + 1 + 647 + 10 + 0 = 666.

It is a super-3 number, since 3×261647100³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261647101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 2445247 + ... + 2445353.

It is an arithmetic number, because the mean of its divisors is an integer number (2369640).

Almost surely, 2^261647100 is an apocalyptic number.

261647100 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 261647100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (511842240).

261647100 is an abundant number, since it is smaller than the sum of its proper divisors (762037380).

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

261647100 is a wasteful number, since it uses less digits than its factorization.

261647100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170 (or 160 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 261647100 is about 16175.5092655533. The cubic root of 261647100 is about 639.5953659726.

The spelling of 261647100 in words is "two hundred sixty-one million, six hundred forty-seven thousand, one hundred".