19218031913 has 2 divisors, whose sum is σ = 19218031914. Its totient is φ = 19218031912.

The previous prime is 19218031891. The next prime is 19218031993. The reversal of 19218031913 is 31913081291.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16203253264 + 3014778649 = 127292^2 + 54907^2 .

It is a cyclic number.

It is not a de Polignac number, because 19218031913 - 2⁶ = 19218031849 is a prime.

It is not a weakly prime, because it can be changed into another prime (19218031993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9609015956 + 9609015957.

It is an arithmetic number, because the mean of its divisors is an integer number (9609015957).

Almost surely, 2^19218031913 is an apocalyptic number.

It is an amenable number.

19218031913 is a deficient number, since it is larger than the sum of its proper divisors (1).

19218031913 is an equidigital number, since it uses as much as digits as its factorization.

19218031913 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 38.

The spelling of 19218031913 in words is "nineteen billion, two hundred eighteen million, thirty-one thousand, nine hundred thirteen".