180638729 has 2 divisors, whose sum is σ = 180638730. Its totient is φ = 180638728.

The previous prime is 180638713. The next prime is 180638789. The reversal of 180638729 is 927836081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 142754704 + 37884025 = 11948^2 + 6155^2 .

It is a cyclic number.

It is not a de Polignac number, because 180638729 - 2⁴ = 180638713 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 180638729.

It is not a weakly prime, because it can be changed into another prime (180638789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90319364 + 90319365.

It is an arithmetic number, because the mean of its divisors is an integer number (90319365).

Almost surely, 2^180638729 is an apocalyptic number.

It is an amenable number.

180638729 is a deficient number, since it is larger than the sum of its proper divisors (1).

180638729 is an equidigital number, since it uses as much as digits as its factorization.

180638729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 180638729 is about 13440.1908096574. The cubic root of 180638729 is about 565.2886811497.

The spelling of 180638729 in words is "one hundred eighty million, six hundred thirty-eight thousand, seven hundred twenty-nine".