18012563 has 4 divisors (see below), whose sum is σ = 18025440. Its totient is φ = 17999688.

The previous prime is 18012559. The next prime is 18012569. The reversal of 18012563 is 36521081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36521081 = 53 ⋅689077.

It is a cyclic number.

It is not a de Polignac number, because 18012563 - 2² = 18012559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18012569) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4043 + ... + 7236.

It is an arithmetic number, because the mean of its divisors is an integer number (4506360).

Almost surely, 2^18012563 is an apocalyptic number.

18012563 is a deficient number, since it is larger than the sum of its proper divisors (12877).

18012563 is a wasteful number, since it uses less digits than its factorization.

18012563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12876.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 18012563 is about 4244.1209926203. The cubic root of 18012563 is about 262.1350963048.

It can be divided in two parts, 18012 and 563, that multiplied together give a triangular number (10140756 = T₄₅₀₃).

The spelling of 18012563 in words is "eighteen million, twelve thousand, five hundred sixty-three".