21921103 has 4 divisors (see below), whose sum is σ = 21964680. Its totient is φ = 21877528.

The previous prime is 21921083. The next prime is 21921113. The reversal of 21921103 is 30112912.

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-21921103 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 (21921113) 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, 21025 + ... + 22042.

It is an arithmetic number, because the mean of its divisors is an integer number (5491170).

Almost surely, 2^21921103 is an apocalyptic number.

21921103 is a deficient number, since it is larger than the sum of its proper divisors (43577).

21921103 is an equidigital number, since it uses as much as digits as its factorization.

21921103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43576.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 21921103 is about 4681.9977573681. The cubic root of 21921103 is about 279.8685735247.

The spelling of 21921103 in words is "twenty-one million, nine hundred twenty-one thousand, one hundred three".