261813600 has 576 divisors, whose sum is σ = 1079930880. Its totient is φ = 60825600.

The previous prime is 261813599. The next prime is 261813611. The reversal of 261813600 is 6318162.

It is a super-2 number, since 2×261813600² = 137092722289920000, which contains 22 as substring.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 8445585 + ... + 8445615.

It is an arithmetic number, because the mean of its divisors is an integer number (1874880).

Almost surely, 2^261813600 is an apocalyptic number.

261813600 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 261813600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (539965440).

261813600 is an abundant number, since it is smaller than the sum of its proper divisors (818117280).

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

261813600 is a wasteful number, since it uses less digits than its factorization.

261813600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100 (or 81 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 261813600 is about 16180.6551165273. The cubic root of 261813600 is about 639.7310067491.

The spelling of 261813600 in words is "two hundred sixty-one million, eight hundred thirteen thousand, six hundred".