18621143 has 2 divisors, whose sum is σ = 18621144. Its totient is φ = 18621142.

The previous prime is 18621139. The next prime is 18621149. The reversal of 18621143 is 34112681.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18621143 - 2² = 18621139 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18621149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9310571 + 9310572.

It is an arithmetic number, because the mean of its divisors is an integer number (9310572).

Almost surely, 2^18621143 is an apocalyptic number.

18621143 is a deficient number, since it is larger than the sum of its proper divisors (1).

18621143 is an equidigital number, since it uses as much as digits as its factorization.

18621143 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 26.

The square root of 18621143 is about 4315.2222422489. Note that the first 4 decimals coincide. The cubic root of 18621143 is about 265.0546606126.

The spelling of 18621143 in words is "eighteen million, six hundred twenty-one thousand, one hundred forty-three".