20768987 has 2 divisors, whose sum is σ = 20768988. Its totient is φ = 20768986.

The previous prime is 20768981. The next prime is 20768999. The reversal of 20768987 is 78986702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20768987 - 2¹⁰ = 20767963 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20768981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10384493 + 10384494.

It is an arithmetic number, because the mean of its divisors is an integer number (10384494).

Almost surely, 2^20768987 is an apocalyptic number.

20768987 is a deficient number, since it is larger than the sum of its proper divisors (1).

20768987 is an equidigital number, since it uses as much as digits as its factorization.

20768987 is an odious number, because the sum of its binary digits is odd.

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

The square root of 20768987 is about 4557.3004070392. The cubic root of 20768987 is about 274.8770226999.

The spelling of 20768987 in words is "twenty million, seven hundred sixty-eight thousand, nine hundred eighty-seven".