21263628 has 24 divisors (see below), whose sum is σ = 49802032. Its totient is φ = 7061184.

The previous prime is 21263623. The next prime is 21263647. The reversal of 21263628 is 82636212.

It is a junction number, because it is equal to n+sod(n) for n = 21263595 and 21263604.

It is not an unprimeable number, because it can be changed into a prime (21263621) 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, 126 + ... + 6522.

Almost surely, 2^21263628 is an apocalyptic number.

It is an amenable number.

21263628 is an abundant number, since it is smaller than the sum of its proper divisors (28538404).

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

21263628 is a wasteful number, since it uses less digits than its factorization.

21263628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6681 (or 6679 counting only the distinct ones).

The product of its digits is 6912, while the sum is 30.

The square root of 21263628 is about 4611.2501558688. The cubic root of 21263628 is about 277.0421115278.

The spelling of 21263628 in words is "twenty-one million, two hundred sixty-three thousand, six hundred twenty-eight".