249705640 has 32 divisors (see below), whose sum is σ = 562452480. Its totient is φ = 99772992.

The previous prime is 249705611. The next prime is 249705647. The reversal of 249705640 is 46507942.

249705640 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 249705640.

It is not an unprimeable number, because it can be changed into a prime (249705647) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 40609 + ... + 46351.

It is an arithmetic number, because the mean of its divisors is an integer number (17576640).

Almost surely, 2^249705640 is an apocalyptic number.

249705640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

249705640 is an abundant number, since it is smaller than the sum of its proper divisors (312746840).

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

249705640 is a wasteful number, since it uses less digits than its factorization.

249705640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6841 (or 6837 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 37.

The square root of 249705640 is about 15802.0770786628. The cubic root of 249705640 is about 629.7131809376.

The spelling of 249705640 in words is "two hundred forty-nine million, seven hundred five thousand, six hundred forty".