251340242 has 4 divisors (see below), whose sum is σ = 377010366. Its totient is φ = 125670120.

The previous prime is 251340211. The next prime is 251340253. The reversal of 251340242 is 242043152.

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., 165611161 + 85729081 = 12869^2 + 9259^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62835059 + ... + 62835062.

Almost surely, 2^251340242 is an apocalyptic number.

251340242 is a deficient number, since it is larger than the sum of its proper divisors (125670124).

251340242 is a wasteful number, since it uses less digits than its factorization.

251340242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125670123.

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 251340242 is about 15853.7138235809. The cubic root of 251340242 is about 631.0842519836.

Adding to 251340242 its reverse (242043152), we get a palindrome (493383394).

The spelling of 251340242 in words is "two hundred fifty-one million, three hundred forty thousand, two hundred forty-two".