261022720 has 88 divisors (see below), whose sum is σ = 715696704. Its totient is φ = 89481216.

The previous prime is 261022717. The next prime is 261022733. The reversal of 261022720 is 27220162.

261022720 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 261022691 and 261022700.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32199 + ... + 39481.

Almost surely, 2^261022720 is an apocalyptic number.

261022720 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 261022720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (357848352).

261022720 is an abundant number, since it is smaller than the sum of its proper divisors (454673984).

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

261022720 is an equidigital number, since it uses as much as digits as its factorization.

261022720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7315 (or 7297 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 261022720 is about 16156.1975724488. The cubic root of 261022720 is about 639.0861958741.

Adding to 261022720 its reverse (27220162), we get a palindrome (288242882).

The spelling of 261022720 in words is "two hundred sixty-one million, twenty-two thousand, seven hundred twenty".