19887213149 has 2 divisors, whose sum is σ = 19887213150. Its totient is φ = 19887213148.

The previous prime is 19887213089. The next prime is 19887213167. The reversal of 19887213149 is 94131278891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17753697049 + 2133516100 = 133243^2 + 46190^2 .

It is a cyclic number.

It is not a de Polignac number, because 19887213149 - 2¹² = 19887209053 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19887213149.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19887215149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9943606574 + 9943606575.

It is an arithmetic number, because the mean of its divisors is an integer number (9943606575).

Almost surely, 2^19887213149 is an apocalyptic number.

It is an amenable number.

19887213149 is a deficient number, since it is larger than the sum of its proper divisors (1).

19887213149 is an equidigital number, since it uses as much as digits as its factorization.

19887213149 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 53.

The spelling of 19887213149 in words is "nineteen billion, eight hundred eighty-seven million, two hundred thirteen thousand, one hundred forty-nine".