18261623 has 2 divisors, whose sum is σ = 18261624. Its totient is φ = 18261622.

The previous prime is 18261611. The next prime is 18261637. The reversal of 18261623 is 32616281.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18261623 - 2⁶ = 18261559 is a prime.

It is equal to p_1166942 and since 18261623 and 1166942 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18261673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9130811 + 9130812.

It is an arithmetic number, because the mean of its divisors is an integer number (9130812).

Almost surely, 2^18261623 is an apocalyptic number.

18261623 is a deficient number, since it is larger than the sum of its proper divisors (1).

18261623 is an equidigital number, since it uses as much as digits as its factorization.

18261623 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 29.

The square root of 18261623 is about 4273.3620253847. The cubic root of 18261623 is about 263.3377522447.

The spelling of 18261623 in words is "eighteen million, two hundred sixty-one thousand, six hundred twenty-three".