21628072 has 16 divisors (see below), whose sum is σ = 40602240. Its totient is φ = 10800816.

The previous prime is 21628031. The next prime is 21628121. The reversal of 21628072 is 27082612.

It is a self number, because there is not a number n which added to its sum of digits gives 21628072.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10953 + ... + 12775.

It is an arithmetic number, because the mean of its divisors is an integer number (2537640).

Almost surely, 2^21628072 is an apocalyptic number.

It is an amenable number.

21628072 is a deficient number, since it is larger than the sum of its proper divisors (18974168).

21628072 is a wasteful number, since it uses less digits than its factorization.

21628072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3312 (or 3308 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 21628072 is about 4650.5991011912. The cubic root of 21628072 is about 278.6159247166.

The spelling of 21628072 in words is "twenty-one million, six hundred twenty-eight thousand, seventy-two".