249647840 has 96 divisors (see below), whose sum is σ = 668697120. Its totient is φ = 87312384.

The previous prime is 249647791. The next prime is 249647851. The reversal of 249647840 is 48746942.

It is a junction number, because it is equal to n+sod(n) for n = 249647791 and 249647800.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36362 + ... + 42678.

It is an arithmetic number, because the mean of its divisors is an integer number (6965595).

Almost surely, 2^249647840 is an apocalyptic number.

249647840 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 249647840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (334348560).

249647840 is an abundant number, since it is smaller than the sum of its proper divisors (419049280).

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

249647840 is a wasteful number, since it uses less digits than its factorization.

249647840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6364 (or 6356 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 44.

The square root of 249647840 is about 15800.2480993179. The cubic root of 249647840 is about 629.6645900841.

The spelling of 249647840 in words is "two hundred forty-nine million, six hundred forty-seven thousand, eight hundred forty".