251386042 has 4 divisors (see below), whose sum is σ = 377079066. Its totient is φ = 125693020.

The previous prime is 251386039. The next prime is 251386043. The reversal of 251386042 is 240683152.

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., 214066161 + 37319881 = 14631^2 + 6109^2 .

It is a super-2 number, since 2×251386042² = 126389884224851528, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 251385995 and 251386013.

It is not an unprimeable number, because it can be changed into a prime (251386043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 62846509 + ... + 62846512.

Almost surely, 2^251386042 is an apocalyptic number.

251386042 is a deficient number, since it is larger than the sum of its proper divisors (125693024).

251386042 is a wasteful number, since it uses less digits than its factorization.

251386042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125693023.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 251386042 is about 15855.1582142847. The cubic root of 251386042 is about 631.1225823667.

The spelling of 251386042 in words is "two hundred fifty-one million, three hundred eighty-six thousand, forty-two".