18101971 has 2 divisors, whose sum is σ = 18101972. Its totient is φ = 18101970.

The previous prime is 18101959. The next prime is 18102013. The reversal of 18101971 is 17910181.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18101971 - 2²¹ = 16004819 is a prime.

It is not a weakly prime, because it can be changed into another prime (18101371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9050985 + 9050986.

It is an arithmetic number, because the mean of its divisors is an integer number (9050986).

Almost surely, 2^18101971 is an apocalyptic number.

18101971 is a deficient number, since it is larger than the sum of its proper divisors (1).

18101971 is an equidigital number, since it uses as much as digits as its factorization.

18101971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 28.

The square root of 18101971 is about 4254.6411129495. The cubic root of 18101971 is about 262.5680960145.

The spelling of 18101971 in words is "eighteen million, one hundred one thousand, nine hundred seventy-one".