21628038 has 16 divisors (see below), whose sum is σ = 43965936. Its totient is φ = 7091040.

The previous prime is 21628031. The next prime is 21628121. The reversal of 21628038 is 83082612.

It is a junction number, because it is equal to n+sod(n) for n = 21627996 and 21628014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21628031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29181 + ... + 29912.

It is an arithmetic number, because the mean of its divisors is an integer number (2747871).

Almost surely, 2^21628038 is an apocalyptic number.

21628038 is an abundant number, since it is smaller than the sum of its proper divisors (22337898).

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

21628038 is a wasteful number, since it uses less digits than its factorization.

21628038 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59159.

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 21628038 is about 4650.5954457467. The cubic root of 21628038 is about 278.6157787189.

The spelling of 21628038 in words is "twenty-one million, six hundred twenty-eight thousand, thirty-eight".