21424064 has 14 divisors (see below), whose sum is σ = 42513504. Its totient is φ = 10712000.

The previous prime is 21424061. The next prime is 21424079. The reversal of 21424064 is 46042412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21424061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 167312 + ... + 167439.

Almost surely, 2^21424064 is an apocalyptic number.

It is an amenable number.

21424064 is a deficient number, since it is larger than the sum of its proper divisors (21089440).

21424064 is an equidigital number, since it uses as much as digits as its factorization.

21424064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334763 (or 334753 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 23.

The square root of 21424064 is about 4628.6136153280. The cubic root of 21424064 is about 277.7371357191.

Adding to 21424064 its reverse (46042412), we get a palindrome (67466476).

The spelling of 21424064 in words is "twenty-one million, four hundred twenty-four thousand, sixty-four".