21424671 has 6 divisors (see below), whose sum is σ = 30946760. Its totient is φ = 14283108.

The previous prime is 21424651. The next prime is 21424679. The reversal of 21424671 is 17642412.

It is not a de Polignac number, because 21424671 - 2⁹ = 21424159 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 (21424679) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1190251 + ... + 1190268.

Almost surely, 2^21424671 is an apocalyptic number.

21424671 is a deficient number, since it is larger than the sum of its proper divisors (9522089).

21424671 is a wasteful number, since it uses less digits than its factorization.

21424671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2380525 (or 2380522 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 21424671 is about 4628.6791852536. The cubic root of 21424671 is about 277.7397587018.

The spelling of 21424671 in words is "twenty-one million, four hundred twenty-four thousand, six hundred seventy-one".