261242400 has 288 divisors, whose sum is σ = 950564160. Its totient is φ = 61931520.

The previous prime is 261242369. The next prime is 261242431. The reversal of 261242400 is 4242162.

It is an interprime number because it is at equal distance from previous prime (261242369) and next prime (261242431).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 775032 + ... + 775368.

It is an arithmetic number, because the mean of its divisors is an integer number (3300570).

Almost surely, 2^261242400 is an apocalyptic number.

261242400 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 261242400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (475282080).

261242400 is an abundant number, since it is smaller than the sum of its proper divisors (689321760).

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

261242400 is a wasteful number, since it uses less digits than its factorization.

261242400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396 (or 383 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 261242400 is about 16162.9947720093. The cubic root of 261242400 is about 639.2654332575.

Adding to 261242400 its reverse (4242162), we get a palindrome (265484562).

The spelling of 261242400 in words is "two hundred sixty-one million, two hundred forty-two thousand, four hundred".