20789687 has 2 divisors, whose sum is σ = 20789688. Its totient is φ = 20789686.

The previous prime is 20789669. The next prime is 20789689. The reversal of 20789687 is 78698702.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20789687 is a prime.

It is a super-2 number, since 2×20789687² = 864422171115938, which contains 22 as substring.

Together with 20789689, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20789689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10394843 + 10394844.

It is an arithmetic number, because the mean of its divisors is an integer number (10394844).

Almost surely, 2^20789687 is an apocalyptic number.

20789687 is a deficient number, since it is larger than the sum of its proper divisors (1).

20789687 is an equidigital number, since it uses as much as digits as its factorization.

20789687 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 338688, while the sum is 47.

The square root of 20789687 is about 4559.5709227953. The cubic root of 20789687 is about 274.9683137045.

The spelling of 20789687 in words is "twenty million, seven hundred eighty-nine thousand, six hundred eighty-seven".