18649971 has 12 divisors (see below), whose sum is σ = 27106248. Its totient is φ = 12356064.

The previous prime is 18649937. The next prime is 18649973. The reversal of 18649971 is 17994681.

It is a happy number.

It is not a de Polignac number, because 18649971 - 2⁶ = 18649907 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18649973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4890 + ... + 7823.

It is an arithmetic number, because the mean of its divisors is an integer number (2258854).

Almost surely, 2^18649971 is an apocalyptic number.

18649971 is a deficient number, since it is larger than the sum of its proper divisors (8456277).

18649971 is a wasteful number, since it uses less digits than its factorization.

18649971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12882 (or 12879 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The square root of 18649971 is about 4318.5612187394. The cubic root of 18649971 is about 265.1913700160.

The spelling of 18649971 in words is "eighteen million, six hundred forty-nine thousand, nine hundred seventy-one".