18947623 has 4 divisors (see below), whose sum is σ = 19052488. Its totient is φ = 18842760.

The previous prime is 18947611. The next prime is 18947629. The reversal of 18947623 is 32674981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32674981 = 71 ⋅460211.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18947623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18947629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52161 + ... + 52522.

It is an arithmetic number, because the mean of its divisors is an integer number (4763122).

Almost surely, 2^18947623 is an apocalyptic number.

18947623 is a deficient number, since it is larger than the sum of its proper divisors (104865).

18947623 is a wasteful number, since it uses less digits than its factorization.

18947623 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104864.

The product of its digits is 72576, while the sum is 40.

The square root of 18947623 is about 4352.8867433004. The cubic root of 18947623 is about 266.5947411922.

The spelling of 18947623 in words is "eighteen million, nine hundred forty-seven thousand, six hundred twenty-three".