18451891943 has 2 divisors, whose sum is σ = 18451891944. Its totient is φ = 18451891942.

The previous prime is 18451891903. The next prime is 18451891961. The reversal of 18451891943 is 34919815481.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18451891943 - 2⁶ = 18451891879 is a prime.

It is a super-2 number, since 2×18451891943² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18451891903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9225945971 + 9225945972.

It is an arithmetic number, because the mean of its divisors is an integer number (9225945972).

Almost surely, 2^18451891943 is an apocalyptic number.

18451891943 is a deficient number, since it is larger than the sum of its proper divisors (1).

18451891943 is an equidigital number, since it uses as much as digits as its factorization.

18451891943 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1244160, while the sum is 53.

The spelling of 18451891943 in words is "eighteen billion, four hundred fifty-one million, eight hundred ninety-one thousand, nine hundred forty-three".