19493550091 has 2 divisors, whose sum is σ = 19493550092. Its totient is φ = 19493550090.

The previous prime is 19493549989. The next prime is 19493550151. The reversal of 19493550091 is 19005539491.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (19005539491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19493550091 - 2¹¹ = 19493548043 is a prime.

It is a super-2 number, since 2×19493550091² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19493550691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9746775045 + 9746775046.

It is an arithmetic number, because the mean of its divisors is an integer number (9746775046).

Almost surely, 2^19493550091 is an apocalyptic number.

19493550091 is a deficient number, since it is larger than the sum of its proper divisors (1).

19493550091 is an equidigital number, since it uses as much as digits as its factorization.

19493550091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 218700, while the sum is 46.

The spelling of 19493550091 in words is "nineteen billion, four hundred ninety-three million, five hundred fifty thousand, ninety-one".