18772139 has 2 divisors, whose sum is σ = 18772140. Its totient is φ = 18772138.

The previous prime is 18772121. The next prime is 18772141. The reversal of 18772139 is 93127781.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18772139 - 2¹⁶ = 18706603 is a prime.

Together with 18772141, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18772339) 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 as a sum of consecutive naturals, namely, 9386069 + 9386070.

It is an arithmetic number, because the mean of its divisors is an integer number (9386070).

Almost surely, 2^18772139 is an apocalyptic number.

18772139 is a deficient number, since it is larger than the sum of its proper divisors (1).

18772139 is an equidigital number, since it uses as much as digits as its factorization.

18772139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21168, while the sum is 38.

The square root of 18772139 is about 4332.6826562766. The cubic root of 18772139 is about 265.7691620496.

The spelling of 18772139 in words is "eighteen million, seven hundred seventy-two thousand, one hundred thirty-nine".