20081987 has 2 divisors, whose sum is σ = 20081988. Its totient is φ = 20081986.

The previous prime is 20081969. The next prime is 20082043. The reversal of 20081987 is 78918002.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20081987 - 2¹⁸ = 19819843 is a prime.

It is not a weakly prime, because it can be changed into another prime (20081587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10040993 + 10040994.

It is an arithmetic number, because the mean of its divisors is an integer number (10040994).

Almost surely, 2^20081987 is an apocalyptic number.

20081987 is a deficient number, since it is larger than the sum of its proper divisors (1).

20081987 is an equidigital number, since it uses as much as digits as its factorization.

20081987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 20081987 is about 4481.2930053724. The cubic root of 20081987 is about 271.8121675737.

Adding to 20081987 its reverse (78918002), we get a palindrome (98999989).

The spelling of 20081987 in words is "twenty million, eighty-one thousand, nine hundred eighty-seven".