20530402987 has 2 divisors, whose sum is σ = 20530402988. Its totient is φ = 20530402986.

The previous prime is 20530402979. The next prime is 20530403087. The reversal of 20530402987 is 78920403502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20530402987 - 2³ = 20530402979 is a prime.

It is not a weakly prime, because it can be changed into another prime (20530402927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10265201493 + 10265201494.

It is an arithmetic number, because the mean of its divisors is an integer number (10265201494).

Almost surely, 2^20530402987 is an apocalyptic number.

20530402987 is a deficient number, since it is larger than the sum of its proper divisors (1).

20530402987 is an equidigital number, since it uses as much as digits as its factorization.

20530402987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 40.

The spelling of 20530402987 in words is "twenty billion, five hundred thirty million, four hundred two thousand, nine hundred eighty-seven".