251040145 has 4 divisors (see below), whose sum is σ = 301248180. Its totient is φ = 200832112.

The previous prime is 251040143. The next prime is 251040157. The reversal of 251040145 is 541040152.

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

It can be written as a sum of positive squares in 2 ways, for example, as 152176896 + 98863249 = 12336^2 + 9943^2 .

It is a cyclic number.

It is not a de Polignac number, because 251040145 - 2¹ = 251040143 is a prime.

It is not an unprimeable number, because it can be changed into a prime (251040143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25104010 + ... + 25104019.

It is an arithmetic number, because the mean of its divisors is an integer number (75312045).

Almost surely, 2^251040145 is an apocalyptic number.

It is an amenable number.

251040145 is a deficient number, since it is larger than the sum of its proper divisors (50208035).

251040145 is an equidigital number, since it uses as much as digits as its factorization.

251040145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50208034.

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 251040145 is about 15844.2464320649. The cubic root of 251040145 is about 630.8329831401.

Adding to 251040145 its reverse (541040152), we get a palindrome (792080297).

The spelling of 251040145 in words is "two hundred fifty-one million, forty thousand, one hundred forty-five".