21129064 has 32 divisors (see below), whose sum is σ = 45496800. Its totient is φ = 9097920.

The previous prime is 21129049. The next prime is 21129067. The reversal of 21129064 is 46092112.

It is not an unprimeable number, because it can be changed into a prime (21129067) 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, 4647 + ... + 7990.

It is an arithmetic number, because the mean of its divisors is an integer number (1421775).

Almost surely, 2^21129064 is an apocalyptic number.

It is an amenable number.

21129064 is an abundant number, since it is smaller than the sum of its proper divisors (24367736).

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

21129064 is a wasteful number, since it uses less digits than its factorization.

21129064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12673 (or 12669 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 21129064 is about 4596.6361613684. The cubic root of 21129064 is about 276.4564665223.

The spelling of 21129064 in words is "twenty-one million, one hundred twenty-nine thousand, sixty-four".