251442 has 24 divisors (see below), whose sum is σ = 556140. Its totient is φ = 82080.

The previous prime is 251437. The next prime is 251443. The reversal of 251442 is 244152.

It can be written as a sum of positive squares in 2 ways, for example, as 251001 + 441 = 501^2 + 21^2 .

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

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 251442.

It is not an unprimeable number, because it can be changed into a prime (251443) by changing a digit.

251442 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 11 ways as a sum of consecutive naturals, for example, 984 + ... + 1212.

2²⁵¹⁴⁴² is an apocalyptic number.

251442 is an abundant number, since it is smaller than the sum of its proper divisors (304698).

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

251442 is a wasteful number, since it uses less digits than its factorization.

251442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298 (or 295 counting only the distinct ones).

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

The square root of 251442 is about 501.4399266114. The cubic root of 251442 is about 63.1169407742.

Adding to 251442 its reverse (244152), we get a palindrome (495594).

It can be divided in two parts, 2514 and 42, that added together give a triangular number (2556 = T₇₁).

The spelling of 251442 in words is "two hundred fifty-one thousand, four hundred forty-two".