21128514 has 32 divisors (see below), whose sum is σ = 46522944. Its totient is φ = 6343680.

The previous prime is 21128507. The next prime is 21128539. The reversal of 21128514 is 41582112.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6042 + ... + 8874.

It is an arithmetic number, because the mean of its divisors is an integer number (1453842).

Almost surely, 2^21128514 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21128514, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23261472).

21128514 is an abundant number, since it is smaller than the sum of its proper divisors (25394430).

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

21128514 is a wasteful number, since it uses less digits than its factorization.

21128514 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2962.

The product of its digits is 640, while the sum is 24.

The square root of 21128514 is about 4596.5763346212. The cubic root of 21128514 is about 276.4540677353.

The spelling of 21128514 in words is "twenty-one million, one hundred twenty-eight thousand, five hundred fourteen".