251628 has 24 divisors (see below), whose sum is σ = 632688. Its totient is φ = 77376.

The previous prime is 251623. The next prime is 251639. The reversal of 251628 is 826152.

It is a junction number, because it is equal to n+sod(n) for n = 251598 and 251607.

It is a congruent number.

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

251628 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 651 + ... + 962.

It is an arithmetic number, because the mean of its divisors is an integer number (26362).

2²⁵¹⁶²⁸ is an apocalyptic number.

It is an amenable number.

251628 is an abundant number, since it is smaller than the sum of its proper divisors (381060).

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

251628 is a wasteful number, since it uses less digits than its factorization.

251628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1633 (or 1631 counting only the distinct ones).

The product of its digits is 960, while the sum is 24.

The square root of 251628 is about 501.6253582107. The cubic root of 251628 is about 63.1325001708.

It can be divided in two parts, 25 and 1628, that added together give a triangular number (1653 = T₅₇).

The spelling of 251628 in words is "two hundred fifty-one thousand, six hundred twenty-eight".