251424 has 60 divisors (see below), whose sum is σ = 747054. Its totient is φ = 82944.

The previous prime is 251417. The next prime is 251429. The reversal of 251424 is 424152.

It can be written as a sum of positive squares in only one way, i.e., 219024 + 32400 = 468^2 + 180^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a plaindrome in base 14.

It is a nialpdrome in base 6.

It is a junction number, because it is equal to n+sod(n) for n = 251397 and 251406.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 251424.

It is not an unprimeable number, because it can be changed into a prime (251429) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 2544 + ... + 2640.

2²⁵¹⁴²⁴ is an apocalyptic number.

251424 is a gapful number since it is divisible by the number (24) 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 251424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (373527).

251424 is an abundant number, since it is smaller than the sum of its proper divisors (495630).

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

251424 is an equidigital number, since it uses as much as digits as its factorization.

251424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119 (or 102 counting only the distinct ones).

The product of its digits is 320, while the sum is 18.

The square root of 251424 is about 501.4219779786. The cubic root of 251424 is about 63.1154346190.

Adding to 251424 its reverse (424152), we get a palindrome (675576).

The spelling of 251424 in words is "two hundred fifty-one thousand, four hundred twenty-four".