261890304 has 144 divisors (see below), whose sum is σ = 795295872. Its totient is φ = 75792384.

The previous prime is 261890303. The next prime is 261890309. The reversal of 261890304 is 403098162.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261890303) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 168957 + ... + 170499.

It is an arithmetic number, because the mean of its divisors is an integer number (5522888).

Almost surely, 2^261890304 is an apocalyptic number.

261890304 is a gapful number since it is divisible by the number (24) 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 261890304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (397647936).

261890304 is an abundant number, since it is smaller than the sum of its proper divisors (533405568).

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

261890304 is a wasteful number, since it uses less digits than its factorization.

261890304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1592 (or 1578 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 261890304 is about 16183.0251807256. The cubic root of 261890304 is about 639.7934750292.

The spelling of 261890304 in words is "two hundred sixty-one million, eight hundred ninety thousand, three hundred four".