251151161 has 4 divisors (see below), whose sum is σ = 252193524. Its totient is φ = 250108800.

The previous prime is 251151143. The next prime is 251151169. The reversal of 251151161 is 161151152.

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 93799225 + 157351936 = 9685^2 + 12544^2 .

It is a cyclic number.

It is not a de Polignac number, because 251151161 - 2¹⁸ = 250889017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251151169) 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, 520820 + ... + 521301.

It is an arithmetic number, because the mean of its divisors is an integer number (63048381).

Almost surely, 2^251151161 is an apocalyptic number.

It is an amenable number.

251151161 is a deficient number, since it is larger than the sum of its proper divisors (1042363).

251151161 is a wasteful number, since it uses less digits than its factorization.

251151161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1042362.

The product of its digits is 300, while the sum is 23.

The square root of 251151161 is about 15847.7493985739. The cubic root of 251151161 is about 630.9259592836.

Subtracting from 251151161 its reverse (161151152), we obtain a palindrome (90000009).

The spelling of 251151161 in words is "two hundred fifty-one million, one hundred fifty-one thousand, one hundred sixty-one".