21603673 has 16 divisors (see below), whose sum is σ = 27212416. Its totient is φ = 16692480.

The previous prime is 21603661. The next prime is 21603733. The reversal of 21603673 is 37630612.

It is a de Polignac number, because none of the positive numbers 2^k-21603673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21603613) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1153 + ... + 6673.

It is an arithmetic number, because the mean of its divisors is an integer number (1700776).

Almost surely, 2^21603673 is an apocalyptic number.

It is an amenable number.

21603673 is a deficient number, since it is larger than the sum of its proper divisors (5608743).

21603673 is a wasteful number, since it uses less digits than its factorization.

21603673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5584.

The product of its (nonzero) digits is 4536, while the sum is 28.

The square root of 21603673 is about 4647.9751505360. The cubic root of 21603673 is about 278.5111148219.

The spelling of 21603673 in words is "twenty-one million, six hundred three thousand, six hundred seventy-three".