261697400 has 48 divisors (see below), whose sum is σ = 612951840. Its totient is φ = 103904000.

The previous prime is 261697399. The next prime is 261697417. The reversal of 261697400 is 4796162.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 22625 + ... + 32175.

It is an arithmetic number, because the mean of its divisors is an integer number (12769830).

Almost surely, 2^261697400 is an apocalyptic number.

261697400 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 261697400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (306475920).

261697400 is an abundant number, since it is smaller than the sum of its proper divisors (351254440).

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

261697400 is a wasteful number, since it uses less digits than its factorization.

261697400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9704 (or 9695 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 261697400 is about 16177.0640105057. The cubic root of 261697400 is about 639.6363494010.

The spelling of 261697400 in words is "two hundred sixty-one million, six hundred ninety-seven thousand, four hundred".