18261568 has 56 divisors (see below), whose sum is σ = 39940992. Its totient is φ = 8231424.

The previous prime is 18261559. The next prime is 18261599. The reversal of 18261568 is 86516281.

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, 38871 + ... + 39337.

It is an arithmetic number, because the mean of its divisors is an integer number (713232).

Almost surely, 2^18261568 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18261568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19970496).

18261568 is an abundant number, since it is smaller than the sum of its proper divisors (21679424).

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

18261568 is a wasteful number, since it uses less digits than its factorization.

18261568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539 (or 529 counting only the distinct ones).

The product of its digits is 23040, while the sum is 37.

The square root of 18261568 is about 4273.3555901656. The cubic root of 18261568 is about 263.3374878726.

The spelling of 18261568 in words is "eighteen million, two hundred sixty-one thousand, five hundred sixty-eight".