21404268 has 18 divisors (see below), whose sum is σ = 54105324. Its totient is φ = 7134744.

The previous prime is 21404267. The next prime is 21404269. The reversal of 21404268 is 86240412.

It is an interprime number because it is at equal distance from previous prime (21404267) and next prime (21404269).

It is a tau number, because it is divible by the number of its divisors (18).

It is not an unprimeable number, because it can be changed into a prime (21404263) 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, 297246 + ... + 297317.

Almost surely, 2^21404268 is an apocalyptic number.

It is an amenable number.

21404268 is an abundant number, since it is smaller than the sum of its proper divisors (32701056).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21404268 is a wasteful number, since it uses less digits than its factorization.

21404268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 594573 (or 594568 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 21404268 is about 4626.4746838170. The cubic root of 21404268 is about 277.6515656076.

The spelling of 21404268 in words is "twenty-one million, four hundred four thousand, two hundred sixty-eight".