18138797 has 2 divisors, whose sum is σ = 18138798. Its totient is φ = 18138796.

The previous prime is 18138767. The next prime is 18138829. The reversal of 18138797 is 79783181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13205956 + 4932841 = 3634^2 + 2221^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18138797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18138707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9069398 + 9069399.

It is an arithmetic number, because the mean of its divisors is an integer number (9069399).

Almost surely, 2^18138797 is an apocalyptic number.

It is an amenable number.

18138797 is a deficient number, since it is larger than the sum of its proper divisors (1).

18138797 is an equidigital number, since it uses as much as digits as its factorization.

18138797 is an evil number, because the sum of its binary digits is even.

The product of its digits is 84672, while the sum is 44.

The square root of 18138797 is about 4258.9666587096. The cubic root of 18138797 is about 262.7460284456.

The spelling of 18138797 in words is "eighteen million, one hundred thirty-eight thousand, seven hundred ninety-seven".