21223673 has 2 divisors, whose sum is σ = 21223674. Its totient is φ = 21223672.

The previous prime is 21223663. The next prime is 21223693. The reversal of 21223673 is 37632212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18292729 + 2930944 = 4277^2 + 1712^2 .

It is a cyclic number.

It is not a de Polignac number, because 21223673 - 2¹⁸ = 20961529 is a prime.

It is a super-2 number, since 2×21223673² = 900888591221858, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21223603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611836 + 10611837.

It is an arithmetic number, because the mean of its divisors is an integer number (10611837).

Almost surely, 2^21223673 is an apocalyptic number.

It is an amenable number.

21223673 is a deficient number, since it is larger than the sum of its proper divisors (1).

21223673 is an equidigital number, since it uses as much as digits as its factorization.

21223673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 26.

The square root of 21223673 is about 4606.9157795645. The cubic root of 21223673 is about 276.8684792272.

Adding to 21223673 its reverse (37632212), we get a palindrome (58855885).

The spelling of 21223673 in words is "twenty-one million, two hundred twenty-three thousand, six hundred seventy-three".