261222528 has 96 divisors (see below), whose sum is σ = 807215760. Its totient is φ = 74629632.

The previous prime is 261222509. The next prime is 261222539. The reversal of 261222528 is 825222162.

It is a tau number, because it is divible by the number of its divisors (96).

It is a junction number, because it is equal to n+sod(n) for n = 261222495 and 261222504.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11875 + ... + 25757.

Almost surely, 2^261222528 is an apocalyptic number.

261222528 is a gapful number since it is divisible by the number (28) 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 261222528, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (403607880).

261222528 is an abundant number, since it is smaller than the sum of its proper divisors (545993232).

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

261222528 is a wasteful number, since it uses less digits than its factorization.

261222528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13914 (or 13895 counting only the distinct ones).

The product of its digits is 7680, while the sum is 30.

The square root of 261222528 is about 16162.3800227565. The cubic root of 261222528 is about 639.2492237846.

The spelling of 261222528 in words is "two hundred sixty-one million, two hundred twenty-two thousand, five hundred twenty-eight".