249661440 has 480 divisors, whose sum is σ = 1046485440. Its totient is φ = 55738368.

The previous prime is 249661393. The next prime is 249661441. The reversal of 249661440 is 44166942.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 249661395 and 249661404.

It is not an unprimeable number, because it can be changed into a prime (249661441) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 5806059 + ... + 5806101.

It is an arithmetic number, because the mean of its divisors is an integer number (2180178).

Almost surely, 2^249661440 is an apocalyptic number.

249661440 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 249661440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (523242720).

249661440 is an abundant number, since it is smaller than the sum of its proper divisors (796824000).

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

249661440 is an equidigital number, since it uses as much as digits as its factorization.

249661440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 249661440 is about 15800.6784664457. The cubic root of 249661440 is about 629.6760239008.

It can be divided in two parts, 2496 and 61440, that added together give a palindrome (63936).

The spelling of 249661440 in words is "two hundred forty-nine million, six hundred sixty-one thousand, four hundred forty".