18994509 has 24 divisors (see below), whose sum is σ = 29165760. Its totient is φ = 11878272.

The previous prime is 18994499. The next prime is 18994529. The reversal of 18994509 is 90549981.

It is not a de Polignac number, because 18994509 - 2⁵ = 18994477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18994529) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18832 + ... + 19814.

It is an arithmetic number, because the mean of its divisors is an integer number (1215240).

Almost surely, 2^18994509 is an apocalyptic number.

18994509 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

18994509 is a deficient number, since it is larger than the sum of its proper divisors (10171251).

18994509 is a wasteful number, since it uses less digits than its factorization.

18994509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1121 (or 1118 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The square root of 18994509 is about 4358.2690371293. The cubic root of 18994509 is about 266.8144567929.

It can be divided in two parts, 18994 and 509, that added together give a triangular number (19503 = T₁₉₇).

The spelling of 18994509 in words is "eighteen million, nine hundred ninety-four thousand, five hundred nine".