21628635 has 32 divisors (see below), whose sum is σ = 40919040. Its totient is φ = 9545088.

The previous prime is 21628627. The next prime is 21628643. The reversal of 21628635 is 53682612.

It is an interprime number because it is at equal distance from previous prime (21628627) and next prime (21628643).

It is not a de Polignac number, because 21628635 - 2³ = 21628627 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21628596 and 21628605.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 507 + ... + 6596.

It is an arithmetic number, because the mean of its divisors is an integer number (1278720).

Almost surely, 2^21628635 is an apocalyptic number.

21628635 is a deficient number, since it is larger than the sum of its proper divisors (19290405).

21628635 is a wasteful number, since it uses less digits than its factorization.

21628635 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7147.

The product of its digits is 17280, while the sum is 33.

The square root of 21628635 is about 4650.6596306331. The cubic root of 21628635 is about 278.6183422445.

The spelling of 21628635 in words is "twenty-one million, six hundred twenty-eight thousand, six hundred thirty-five".