145681 has 2 divisors, whose sum is σ = 145682. Its totient is φ = 145680.

The previous prime is 145679. The next prime is 145687. The reversal of 145681 is 186541.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80656 + 65025 = 284^2 + 255^2 .

It is a cyclic number.

It is not a de Polignac number, because 145681 - 2¹ = 145679 is a prime.

It is a super-2 number, since 2×145681² = 42445907522, which contains 22 as substring.

Together with 145679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (145687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72840 + 72841.

It is an arithmetic number, because the mean of its divisors is an integer number (72841).

2¹⁴⁵⁶⁸¹ is an apocalyptic number.

It is an amenable number.

145681 is a deficient number, since it is larger than the sum of its proper divisors (1).

145681 is an equidigital number, since it uses as much as digits as its factorization.

145681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 960, while the sum is 25.

The square root of 145681 is about 381.6818046488. The cubic root of 145681 is about 52.6179961265.

Adding to 145681 its product of digits (960), we get a palindrome (146641).

The spelling of 145681 in words is "one hundred forty-five thousand, six hundred eighty-one".