261490320 has 360 divisors, whose sum is σ = 1090305216. Its totient is φ = 54991872.

The previous prime is 261490309. The next prime is 261490321. The reversal of 261490320 is 23094162.

It is a tau number, because it is divible by the number of its divisors (360).

It is not an unprimeable number, because it can be changed into a prime (261490321) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 851607 + ... + 851913.

Almost surely, 2^261490320 is an apocalyptic number.

261490320 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 261490320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (545152608).

261490320 is an abundant number, since it is smaller than the sum of its proper divisors (828814896).

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

261490320 is a wasteful number, since it uses less digits than its factorization.

261490320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359 (or 337 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 261490320 is about 16170.6623240979. The cubic root of 261490320 is about 639.4675910719.

The spelling of 261490320 in words is "two hundred sixty-one million, four hundred ninety thousand, three hundred twenty".