18391935971 has 2 divisors, whose sum is σ = 18391935972. Its totient is φ = 18391935970.

The previous prime is 18391935953. The next prime is 18391936001. The reversal of 18391935971 is 17953919381.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18391935971 - 2⁶ = 18391935907 is a prime.

It is a super-2 number, since 2×18391935971² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18391934971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9195967985 + 9195967986.

It is an arithmetic number, because the mean of its divisors is an integer number (9195967986).

Almost surely, 2^18391935971 is an apocalyptic number.

18391935971 is a deficient number, since it is larger than the sum of its proper divisors (1).

18391935971 is an equidigital number, since it uses as much as digits as its factorization.

18391935971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1837080, while the sum is 56.

The spelling of 18391935971 in words is "eighteen billion, three hundred ninety-one million, nine hundred thirty-five thousand, nine hundred seventy-one".