21421068 has 24 divisors (see below), whose sum is σ = 50140272. Its totient is φ = 7117824.

The previous prime is 21421061. The next prime is 21421091. The reversal of 21421068 is 86012412.

It is not an unprimeable number, because it can be changed into a prime (21421061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1396 + ... + 6692.

It is an arithmetic number, because the mean of its divisors is an integer number (2089178).

Almost surely, 2^21421068 is an apocalyptic number.

It is an amenable number.

21421068 is an abundant number, since it is smaller than the sum of its proper divisors (28719204).

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

21421068 is a wasteful number, since it uses less digits than its factorization.

21421068 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5641 (or 5639 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 21421068 is about 4628.2899649871. The cubic root of 21421068 is about 277.7241886074.

The spelling of 21421068 in words is "twenty-one million, four hundred twenty-one thousand, sixty-eight".