251620 has 24 divisors (see below), whose sum is σ = 552384. Its totient is φ = 96096.

The previous prime is 251611. The next prime is 251621. The reversal of 251620 is 26152.

It is a happy number.

It is a plaindrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 251594 and 251603.

It is not an unprimeable number, because it can be changed into a prime (251621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 187 + ... + 733.

It is an arithmetic number, because the mean of its divisors is an integer number (23016).

2²⁵¹⁶²⁰ is an apocalyptic number.

251620 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 251620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (276192).

251620 is an abundant number, since it is smaller than the sum of its proper divisors (300764).

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

251620 is a wasteful number, since it uses less digits than its factorization.

251620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579 (or 577 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 251620 is about 501.6173840688. The cubic root of 251620 is about 63.1318311073.

Adding to 251620 its reverse (26152), we get a palindrome (277772).

The spelling of 251620 in words is "two hundred fifty-one thousand, six hundred twenty".