18055397 has 2 divisors, whose sum is σ = 18055398. Its totient is φ = 18055396.

The previous prime is 18055393. The next prime is 18055409. The reversal of 18055397 is 79355081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12737761 + 5317636 = 3569^2 + 2306^2 .

It is a cyclic number.

It is not a de Polignac number, because 18055397 - 2² = 18055393 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18055397.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18055393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9027698 + 9027699.

It is an arithmetic number, because the mean of its divisors is an integer number (9027699).

Almost surely, 2^18055397 is an apocalyptic number.

It is an amenable number.

18055397 is a deficient number, since it is larger than the sum of its proper divisors (1).

18055397 is an equidigital number, since it uses as much as digits as its factorization.

18055397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 37800, while the sum is 38.

The square root of 18055397 is about 4249.1642707714. The cubic root of 18055397 is about 262.3427181765.

The spelling of 18055397 in words is "eighteen million, fifty-five thousand, three hundred ninety-seven".