251661141 has 8 divisors (see below), whose sum is σ = 372831360. Its totient is φ = 167774076.

The previous prime is 251661139. The next prime is 251661199. The reversal of 251661141 is 141166152.

251661141 is a `hidden beast` number, since 2 + 5 + 1 + 6 + 611 + 41 = 666.

It is not a de Polignac number, because 251661141 - 2¹ = 251661139 is a prime.

It is a super-4 number, since 4×251661141⁴ (a number of 35 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 9320783 = 251661141 / (2 + 5 + 1 + 6 + 6 + 1 + 1 + 4 + 1).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251661341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4660365 + ... + 4660418.

It is an arithmetic number, because the mean of its divisors is an integer number (46603920).

Almost surely, 2^251661141 is an apocalyptic number.

It is an amenable number.

251661141 is a deficient number, since it is larger than the sum of its proper divisors (121170219).

251661141 is an equidigital number, since it uses as much as digits as its factorization.

251661141 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9320792 (or 9320786 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 251661141 is about 15863.8312207361. The cubic root of 251661141 is about 631.3527169908.

The spelling of 251661141 in words is "two hundred fifty-one million, six hundred sixty-one thousand, one hundred forty-one".