16638731 has 2 divisors, whose sum is σ = 16638732. Its totient is φ = 16638730.

The previous prime is 16638719. The next prime is 16638749. The reversal of 16638731 is 13783661.

It is a weak prime.

It is an emirp because it is prime and its reverse (13783661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16638731 is a prime.

It is a super-2 number, since 2×16638731² = 553694738580722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 16638691 and 16638700.

It is not a weakly prime, because it can be changed into another prime (16638751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8319365 + 8319366.

It is an arithmetic number, because the mean of its divisors is an integer number (8319366).

Almost surely, 2^16638731 is an apocalyptic number.

16638731 is a deficient number, since it is larger than the sum of its proper divisors (1).

16638731 is an equidigital number, since it uses as much as digits as its factorization.

16638731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18144, while the sum is 35.

The square root of 16638731 is about 4079.0600632989. The cubic root of 16638731 is about 255.2936818872.

The spelling of 16638731 in words is "sixteen million, six hundred thirty-eight thousand, seven hundred thirty-one".