18349947 has 24 divisors (see below), whose sum is σ = 33047040. Its totient is φ = 9532080.

The previous prime is 18349939. The next prime is 18349963. The reversal of 18349947 is 74994381.

It is not a de Polignac number, because 18349947 - 2³ = 18349939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18349927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12547 + ... + 13932.

It is an arithmetic number, because the mean of its divisors is an integer number (1376960).

Almost surely, 2^18349947 is an apocalyptic number.

18349947 is a deficient number, since it is larger than the sum of its proper divisors (14697093).

18349947 is a wasteful number, since it uses less digits than its factorization.

18349947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26503 (or 26500 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 18349947 is about 4283.6838118610. The cubic root of 18349947 is about 263.7616219432.

It can be divided in two parts, 1834 and 9947, that added together give a triangular number (11781 = T₁₅₃).

The spelling of 18349947 in words is "eighteen million, three hundred forty-nine thousand, nine hundred forty-seven".