251344240 has 40 divisors (see below), whose sum is σ = 667859040. Its totient is φ = 86174976.

The previous prime is 251344237. The next prime is 251344243. The reversal of 251344240 is 42443152.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (251344237) and next prime (251344243).

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251344243) 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 7 ways as a sum of consecutive naturals, for example, 223855 + ... + 224974.

It is an arithmetic number, because the mean of its divisors is an integer number (16696476).

Almost surely, 2^251344240 is an apocalyptic number.

251344240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251344240 is an abundant number, since it is smaller than the sum of its proper divisors (416514800).

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

251344240 is a wasteful number, since it uses less digits than its factorization.

251344240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448849 (or 448843 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 25.

The square root of 251344240 is about 15853.8399134090. The cubic root of 251344240 is about 631.0875981270.

Adding to 251344240 its reverse (42443152), we get a palindrome (293787392).

The spelling of 251344240 in words is "two hundred fifty-one million, three hundred forty-four thousand, two hundred forty".