18621271 has 2 divisors, whose sum is σ = 18621272. Its totient is φ = 18621270.

The previous prime is 18621263. The next prime is 18621289. The reversal of 18621271 is 17212681.

It is a weak prime.

It is an emirp because it is prime and its reverse (17212681) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18621271 - 2³ = 18621263 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18621221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9310635 + 9310636.

It is an arithmetic number, because the mean of its divisors is an integer number (9310636).

Almost surely, 2^18621271 is an apocalyptic number.

18621271 is a deficient number, since it is larger than the sum of its proper divisors (1).

18621271 is an equidigital number, since it uses as much as digits as its factorization.

18621271 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1344, while the sum is 28.

The square root of 18621271 is about 4315.2370734410. The cubic root of 18621271 is about 265.0552679315.

The spelling of 18621271 in words is "eighteen million, six hundred twenty-one thousand, two hundred seventy-one".