406688729 has 2 divisors, whose sum is σ = 406688730. Its totient is φ = 406688728.

The previous prime is 406688707. The next prime is 406688731. The reversal of 406688729 is 927886604.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 406627225 + 61504 = 20165^2 + 248^2 .

It is a cyclic number.

It is not a de Polignac number, because 406688729 - 2²⁰ = 405640153 is a prime.

It is a Sophie Germain prime.

Together with 406688731, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (406682729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203344364 + 203344365.

It is an arithmetic number, because the mean of its divisors is an integer number (203344365).

Almost surely, 2^406688729 is an apocalyptic number.

It is an amenable number.

406688729 is a deficient number, since it is larger than the sum of its proper divisors (1).

406688729 is an equidigital number, since it uses as much as digits as its factorization.

406688729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1161216, while the sum is 50.

The square root of 406688729 is about 20166.5249609346. The cubic root of 406688729 is about 740.8905330683.

The spelling of 406688729 in words is "four hundred six million, six hundred eighty-eight thousand, seven hundred twenty-nine".