249561856 has 36 divisors (see below), whose sum is σ = 502615512. Its totient is φ = 123662336.

The previous prime is 249561841. The next prime is 249561857. The reversal of 249561856 is 658165942.

It is a super-2 number, since 2×249561856² = 124562239940329472, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (249561857) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24615 + ... + 33241.

It is an arithmetic number, because the mean of its divisors is an integer number (13961542).

Almost surely, 2^249561856 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 249561856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (251307756).

249561856 is an abundant number, since it is smaller than the sum of its proper divisors (253053656).

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

249561856 is an equidigital number, since it uses as much as digits as its factorization.

249561856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8756 (or 8742 counting only the distinct ones).

The product of its digits is 518400, while the sum is 46.

The square root of 249561856 is about 15797.5268950554. The cubic root of 249561856 is about 629.5922918458.

The spelling of 249561856 in words is "two hundred forty-nine million, five hundred sixty-one thousand, eight hundred fifty-six".