21845628 has 36 divisors (see below), whose sum is σ = 63110320. Its totient is φ = 6241536.

The previous prime is 21845627. The next prime is 21845689. The reversal of 21845628 is 82654812.

21845628 is a `hidden beast` number, since 21 + 8 + 4 + 5 + 628 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21845592 and 21845601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21845627) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43093 + ... + 43596.

Almost surely, 2^21845628 is an apocalyptic number.

21845628 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21845628 is an abundant number, since it is smaller than the sum of its proper divisors (41264692).

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

21845628 is a wasteful number, since it uses less digits than its factorization.

21845628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86706 (or 86701 counting only the distinct ones).

The product of its digits is 30720, while the sum is 36.

The square root of 21845628 is about 4673.9306798454. The cubic root of 21845628 is about 279.5470056194.

The spelling of 21845628 in words is "twenty-one million, eight hundred forty-five thousand, six hundred twenty-eight".