18642623 has 2 divisors, whose sum is σ = 18642624. Its totient is φ = 18642622.

The previous prime is 18642601. The next prime is 18642641. The reversal of 18642623 is 32624681.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18642623 - 2⁸ = 18642367 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18642623.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18642223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9321311 + 9321312.

It is an arithmetic number, because the mean of its divisors is an integer number (9321312).

Almost surely, 2^18642623 is an apocalyptic number.

18642623 is a deficient number, since it is larger than the sum of its proper divisors (1).

18642623 is an equidigital number, since it uses as much as digits as its factorization.

18642623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 32.

The square root of 18642623 is about 4317.7103886203. The cubic root of 18642623 is about 265.1565373942.

The spelling of 18642623 in words is "eighteen million, six hundred forty-two thousand, six hundred twenty-three".