18153997 has 2 divisors, whose sum is σ = 18153998. Its totient is φ = 18153996.

The previous prime is 18153979. The next prime is 18154033. The reversal of 18153997 is 79935181.

Together with previous prime (18153979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12859396 + 5294601 = 3586^2 + 2301^2 .

It is an emirp because it is prime and its reverse (79935181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18153997 - 2¹¹ = 18151949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18153907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9076998 + 9076999.

It is an arithmetic number, because the mean of its divisors is an integer number (9076999).

Almost surely, 2^18153997 is an apocalyptic number.

It is an amenable number.

18153997 is a deficient number, since it is larger than the sum of its proper divisors (1).

18153997 is an equidigital number, since it uses as much as digits as its factorization.

18153997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 68040, while the sum is 43.

The square root of 18153997 is about 4260.7507554421. The cubic root of 18153997 is about 262.8194001727.

The spelling of 18153997 in words is "eighteen million, one hundred fifty-three thousand, nine hundred ninety-seven".