253681 has 2 divisors, whose sum is σ = 253682.
Its totient is φ = 253680.
The previous prime is 253679. The next prime is 253703. The reversal of 253681 is 186352.
It is a happy number.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 207025 + 46656 = 455^2 + 216^2
It is a cyclic number.
It is not a de Polignac number, because 253681 - 21 = 253679 is a prime.
It is a super-2 number, since 2×2536812 = 128708099522, which contains 22 as substring.
Together with 253679, it forms a pair of twin primes.
It is not a weakly prime, because it can be changed into another prime (253601) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (13) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 126840 + 126841.
It is an arithmetic number, because the mean of its divisors is an integer number (126841).
2253681 is an apocalyptic number.
It is an amenable number.
253681 is a deficient number, since it is larger than the sum of its proper divisors (1).
253681 is an equidigital number, since it uses as much as digits as its factorization.
253681 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 1440, while the sum is 25.
The square root of 253681 is about 503.6675490837.
The cubic root of 253681 is about 63.3037319347.
The spelling of 253681 in words is "two hundred fifty-three thousand, six hundred eighty-one".