261145600 has 99 divisors (see below), whose sum is σ = 653797471. Its totient is φ = 103424000.

The previous prime is 261145589. The next prime is 261145613. The reversal of 261145600 is 6541162.

The square root of 261145600 is 16160.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 48219136 + 212926464 = 6944^2 + 14592^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2585550 + ... + 2585650.

Almost surely, 2^261145600 is an apocalyptic number.

261145600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

261145600 is the 16160-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261145600

261145600 is an abundant number, since it is smaller than the sum of its proper divisors (392651871).

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

261145600 is an equidigital number, since it uses as much as digits as its factorization.

261145600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The cubic root of 261145600 is about 639.1864663178.

Multiplying 261145600 by its sum of digits (25), we get a square (6528640000 = 80800²).

261145600 divided by its sum of digits (25) gives a square (10445824 = 3232²).

Adding to 261145600 its reverse (6541162), we get a palindrome (267686762).

The spelling of 261145600 in words is "two hundred sixty-one million, one hundred forty-five thousand, six hundred".