451681 has 2 divisors, whose sum is σ = 451682. Its totient is φ = 451680.

The previous prime is 451679. The next prime is 451691. The reversal of 451681 is 186154.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 349281 + 102400 = 591^2 + 320^2 .

It is a cyclic number.

It is not a de Polignac number, because 451681 - 2¹ = 451679 is a prime.

It is a super-2 number, since 2×451681² = 408031451522, which contains 22 as substring.

Together with 451679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (451601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 225840 + 225841.

It is an arithmetic number, because the mean of its divisors is an integer number (225841).

2⁴⁵¹⁶⁸¹ is an apocalyptic number.

It is an amenable number.

451681 is a deficient number, since it is larger than the sum of its proper divisors (1).

451681 is an equidigital number, since it uses as much as digits as its factorization.

451681 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 451681 is about 672.0721687438. The cubic root of 451681 is about 76.7262443854.

The spelling of 451681 in words is "four hundred fifty-one thousand, six hundred eighty-one".