66644503 has 4 divisors (see below), whose sum is σ = 66979600. Its totient is φ = 66309408.

The previous prime is 66644483. The next prime is 66644507. The reversal of 66644503 is 30544666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66644503 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 (66644507) 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, 167250 + ... + 167647.

It is an arithmetic number, because the mean of its divisors is an integer number (16744900).

Almost surely, 2^66644503 is an apocalyptic number.

66644503 is a deficient number, since it is larger than the sum of its proper divisors (335097).

66644503 is a wasteful number, since it uses less digits than its factorization.

66644503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335096.

The product of its (nonzero) digits is 51840, while the sum is 34.

The square root of 66644503 is about 8163.6084545990. The cubic root of 66644503 is about 405.4351934252.

The spelling of 66644503 in words is "sixty-six million, six hundred forty-four thousand, five hundred three".