18771139971 has 12 divisors (see below), whose sum is σ = 27382324320. Its totient is φ = 12390190800.

The previous prime is 18771139969. The next prime is 18771139973. The reversal of 18771139971 is 17993117781.

It is a happy number.

18771139971 is a `hidden beast` number, since 187 + 7 + 1 + 1 + 399 + 71 = 666.

It is an interprime number because it is at equal distance from previous prime (18771139969) and next prime (18771139973).

It is not a de Polignac number, because 18771139971 - 2¹ = 18771139969 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18771139973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10324251 + ... + 10326068.

It is an arithmetic number, because the mean of its divisors is an integer number (2281860360).

Almost surely, 2^18771139971 is an apocalyptic number.

18771139971 is a deficient number, since it is larger than the sum of its proper divisors (8611184349).

18771139971 is a wasteful number, since it uses less digits than its factorization.

18771139971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20650426 (or 20650423 counting only the distinct ones).

The product of its digits is 666792, while the sum is 54.

The spelling of 18771139971 in words is "eighteen billion, seven hundred seventy-one million, one hundred thirty-nine thousand, nine hundred seventy-one".