21045628 has 12 divisors (see below), whose sum is σ = 37728432. Its totient is φ = 10266080.

The previous prime is 21045617. The next prime is 21045641. The reversal of 21045628 is 82654012.

It is a junction number, because it is equal to n+sod(n) for n = 21045596 and 21045605.

It is a congruent number.

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, 64000 + ... + 64327.

It is an arithmetic number, because the mean of its divisors is an integer number (3144036).

Almost surely, 2^21045628 is an apocalyptic number.

It is an amenable number.

21045628 is a deficient number, since it is larger than the sum of its proper divisors (16682804).

21045628 is a wasteful number, since it uses less digits than its factorization.

21045628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128372 (or 128370 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 21045628 is about 4587.5514166056. The cubic root of 21045628 is about 276.0920892732.

The spelling of 21045628 in words is "twenty-one million, forty-five thousand, six hundred twenty-eight".