251601 has 8 divisors (see below), whose sum is σ = 383424. Its totient is φ = 143760.

The previous prime is 251567. The next prime is 251609. The reversal of 251601 is 106152.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 251601 - 2⁷ = 251473 is a prime.

251601 is a lucky number.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (251609) 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, 5970 + ... + 6011.

It is an arithmetic number, because the mean of its divisors is an integer number (47928).

2²⁵¹⁶⁰¹ is an apocalyptic number.

251601 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

251601 is a deficient number, since it is larger than the sum of its proper divisors (131823).

251601 is a wasteful number, since it uses less digits than its factorization.

251601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11991.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 251601 is about 501.5984449737. The cubic root of 251601 is about 63.1302420246.

Adding to 251601 its reverse (106152), we get a palindrome (357753).

The spelling of 251601 in words is "two hundred fifty-one thousand, six hundred one".