18936969091 has 2 divisors, whose sum is σ = 18936969092. Its totient is φ = 18936969090.

The previous prime is 18936969089. The next prime is 18936969113. The reversal of 18936969091 is 19096963981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18936969091 - 2¹ = 18936969089 is a prime.

Together with 18936969089, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18936969031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9468484545 + 9468484546.

It is an arithmetic number, because the mean of its divisors is an integer number (9468484546).

Almost surely, 2^18936969091 is an apocalyptic number.

18936969091 is a deficient number, since it is larger than the sum of its proper divisors (1).

18936969091 is an equidigital number, since it uses as much as digits as its factorization.

18936969091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5668704, while the sum is 61.

The spelling of 18936969091 in words is "eighteen billion, nine hundred thirty-six million, nine hundred sixty-nine thousand, ninety-one".