729018251681 has 2 divisors, whose sum is σ = 729018251682. Its totient is φ = 729018251680.

The previous prime is 729018251581. The next prime is 729018251683. The reversal of 729018251681 is 186152810927.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 607283552656 + 121734699025 = 779284^2 + 348905^2 .

It is an emirp because it is prime and its reverse (186152810927) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 729018251681 - 2¹⁸ = 729017989537 is a prime.

It is a super-2 number, since 2×729018251681² (a number of 25 digits) contains 22 as substring.

Together with 729018251683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (729018251683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 364509125840 + 364509125841.

It is an arithmetic number, because the mean of its divisors is an integer number (364509125841).

Almost surely, 2^729018251681 is an apocalyptic number.

It is an amenable number.

729018251681 is a deficient number, since it is larger than the sum of its proper divisors (1).

729018251681 is an equidigital number, since it uses as much as digits as its factorization.

729018251681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 483840, while the sum is 50.

The spelling of 729018251681 in words is "seven hundred twenty-nine billion, eighteen million, two hundred fifty-one thousand, six hundred eighty-one".