20002691 has 2 divisors, whose sum is σ = 20002692. Its totient is φ = 20002690.

The previous prime is 20002679. The next prime is 20002729. The reversal of 20002691 is 19620002.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20002691 is a prime.

It is not a weakly prime, because it can be changed into another prime (20002651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10001345 + 10001346.

It is an arithmetic number, because the mean of its divisors is an integer number (10001346).

Almost surely, 2^20002691 is an apocalyptic number.

20002691 is a deficient number, since it is larger than the sum of its proper divisors (1).

20002691 is an equidigital number, since it uses as much as digits as its factorization.

20002691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 20002691 is about 4472.4368078264. The cubic root of 20002691 is about 271.4539352765.

Adding to 20002691 its reverse (19620002), we get a palindrome (39622693).

The spelling of 20002691 in words is "twenty million, two thousand, six hundred ninety-one".