18887203477 has 2 divisors, whose sum is σ = 18887203478. Its totient is φ = 18887203476.

The previous prime is 18887203469. The next prime is 18887203519. The reversal of 18887203477 is 77430278881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14734560996 + 4152642481 = 121386^2 + 64441^2 .

It is an emirp because it is prime and its reverse (77430278881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18887203477 - 2³ = 18887203469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18887203417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9443601738 + 9443601739.

It is an arithmetic number, because the mean of its divisors is an integer number (9443601739).

Almost surely, 2^18887203477 is an apocalyptic number.

It is an amenable number.

18887203477 is a deficient number, since it is larger than the sum of its proper divisors (1).

18887203477 is an equidigital number, since it uses as much as digits as its factorization.

18887203477 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4214784, while the sum is 55.

The spelling of 18887203477 in words is "eighteen billion, eight hundred eighty-seven million, two hundred three thousand, four hundred seventy-seven".