21423908 has 12 divisors (see below), whose sum is σ = 40900272. Its totient is φ = 9738120.

The previous prime is 21423907. The next prime is 21423917. The reversal of 21423908 is 80932412.

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 3 ways as a sum of consecutive naturals, for example, 243410 + ... + 243497.

It is an arithmetic number, because the mean of its divisors is an integer number (3408356).

Almost surely, 2^21423908 is an apocalyptic number.

It is an amenable number.

21423908 is a deficient number, since it is larger than the sum of its proper divisors (19476364).

21423908 is a wasteful number, since it uses less digits than its factorization.

21423908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486922 (or 486920 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 21423908 is about 4628.5967635991. The cubic root of 21423908 is about 277.7364616002.

The spelling of 21423908 in words is "twenty-one million, four hundred twenty-three thousand, nine hundred eight".