21673271 has 2 divisors, whose sum is σ = 21673272. Its totient is φ = 21673270.

The previous prime is 21673261. The next prime is 21673277. The reversal of 21673271 is 17237612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21673271 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21673277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10836635 + 10836636.

It is an arithmetic number, because the mean of its divisors is an integer number (10836636).

Almost surely, 2^21673271 is an apocalyptic number.

21673271 is a deficient number, since it is larger than the sum of its proper divisors (1).

21673271 is an equidigital number, since it uses as much as digits as its factorization.

21673271 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3528, while the sum is 29.

The square root of 21673271 is about 4655.4560464040. The cubic root of 21673271 is about 278.8098763369.

The spelling of 21673271 in words is "twenty-one million, six hundred seventy-three thousand, two hundred seventy-one".