251642 has 4 divisors (see below), whose sum is σ = 377466. Its totient is φ = 125820.

The previous prime is 251639. The next prime is 251653. The reversal of 251642 is 246152.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 229441 + 22201 = 479^2 + 149^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 251642.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62909 + ... + 62912.

2²⁵¹⁶⁴² is an apocalyptic number.

251642 is a deficient number, since it is larger than the sum of its proper divisors (125824).

251642 is a wasteful number, since it uses less digits than its factorization.

251642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125823.

The product of its digits is 480, while the sum is 20.

The square root of 251642 is about 501.6393126540. The cubic root of 251642 is about 63.1336709979.

Adding to 251642 its reverse (246152), we get a palindrome (497794).

The spelling of 251642 in words is "two hundred fifty-one thousand, six hundred forty-two".