66003563 has 4 divisors (see below), whose sum is σ = 67613448. Its totient is φ = 64393680.

The previous prime is 66003559. The next prime is 66003611. The reversal of 66003563 is 36530066.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 36530066 = 2 ⋅18265033.

It is a cyclic number.

It is not a de Polignac number, because 66003563 - 2² = 66003559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66003263) 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, 804881 + ... + 804962.

It is an arithmetic number, because the mean of its divisors is an integer number (16903362).

Almost surely, 2^66003563 is an apocalyptic number.

66003563 is a deficient number, since it is larger than the sum of its proper divisors (1609885).

66003563 is a wasteful number, since it uses less digits than its factorization.

66003563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1609884.

The product of its (nonzero) digits is 9720, while the sum is 29.

The square root of 66003563 is about 8124.2576891677. The cubic root of 66003563 is about 404.1312741224.

It can be divided in two parts, 66003 and 563, that added together give a palindrome (66566).

The spelling of 66003563 in words is "sixty-six million, three thousand, five hundred sixty-three".