21973603 has 4 divisors (see below), whose sum is σ = 22333888. Its totient is φ = 21613320.

The previous prime is 21973591. The next prime is 21973607. The reversal of 21973603 is 30637912.

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-21973603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21973607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 180051 + ... + 180172.

It is an arithmetic number, because the mean of its divisors is an integer number (5583472).

Almost surely, 2^21973603 is an apocalyptic number.

21973603 is a deficient number, since it is larger than the sum of its proper divisors (360285).

21973603 is an equidigital number, since it uses as much as digits as its factorization.

21973603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360284.

The product of its (nonzero) digits is 6804, while the sum is 31.

The square root of 21973603 is about 4687.6009855789. The cubic root of 21973603 is about 280.0918193765.

The spelling of 21973603 in words is "twenty-one million, nine hundred seventy-three thousand, six hundred three".