249445840 has 80 divisors (see below), whose sum is σ = 684241920. Its totient is φ = 82759680.

The previous prime is 249445831. The next prime is 249445841. The reversal of 249445840 is 48544942.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 249445793 and 249445802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (249445841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10176 + ... + 24544.

It is an arithmetic number, because the mean of its divisors is an integer number (8553024).

Almost surely, 2^249445840 is an apocalyptic number.

249445840 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 249445840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (342120960).

249445840 is an abundant number, since it is smaller than the sum of its proper divisors (434796080).

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

249445840 is a wasteful number, since it uses less digits than its factorization.

249445840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14420 (or 14414 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 40.

The square root of 249445840 is about 15793.8545010393. The cubic root of 249445840 is about 629.4947153677.

The spelling of 249445840 in words is "two hundred forty-nine million, four hundred forty-five thousand, eight hundred forty".