251155442 has 4 divisors (see below), whose sum is σ = 376733166. Its totient is φ = 125577720.

The previous prime is 251155417. The next prime is 251155481. The reversal of 251155442 is 244551152.

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., 206813161 + 44342281 = 14381^2 + 6659^2 .

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, 62788859 + ... + 62788862.

Almost surely, 2^251155442 is an apocalyptic number.

251155442 is a deficient number, since it is larger than the sum of its proper divisors (125577724).

251155442 is a wasteful number, since it uses less digits than its factorization.

251155442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125577723.

The product of its digits is 8000, while the sum is 29.

The square root of 251155442 is about 15847.8844644956. The cubic root of 251155442 is about 630.9295440818.

The spelling of 251155442 in words is "two hundred fifty-one million, one hundred fifty-five thousand, four hundred forty-two".