251400242 has 4 divisors (see below), whose sum is σ = 377100366. Its totient is φ = 125700120.

The previous prime is 251400209. The next prime is 251400257. The reversal of 251400242 is 242004152.

It is a happy number.

251400242 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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., 223532401 + 27867841 = 14951^2 + 5279^2 .

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, 62850059 + ... + 62850062.

Almost surely, 2^251400242 is an apocalyptic number.

251400242 is a deficient number, since it is larger than the sum of its proper divisors (125700124).

251400242 is a wasteful number, since it uses less digits than its factorization.

251400242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125700123.

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 251400242 is about 15855.6060117550. The cubic root of 251400242 is about 631.1344655138.

Adding to 251400242 its reverse (242004152), we get a palindrome (493404394).

The spelling of 251400242 in words is "two hundred fifty-one million, four hundred thousand, two hundred forty-two".