21423927 has 24 divisors (see below), whose sum is σ = 35187696. Its totient is φ = 11520768.

The previous prime is 21423917. The next prime is 21423959. The reversal of 21423927 is 72932412.

It is not a de Polignac number, because 21423927 - 2⁶ = 21423863 is a prime.

21423927 is a modest number, since divided by 3927 gives 2142 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 21423894 and 21423903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21423907) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1788 + ... + 6785.

It is an arithmetic number, because the mean of its divisors is an integer number (1466154).

Almost surely, 2^21423927 is an apocalyptic number.

21423927 is a deficient number, since it is larger than the sum of its proper divisors (13763769).

21423927 is a wasteful number, since it uses less digits than its factorization.

21423927 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8607 (or 8600 counting only the distinct ones).

The product of its digits is 6048, while the sum is 30.

The square root of 21423927 is about 4628.5988160565. The cubic root of 21423927 is about 277.7365437046.

The spelling of 21423927 in words is "twenty-one million, four hundred twenty-three thousand, nine hundred twenty-seven".