21746828 has 12 divisors (see below), whose sum is σ = 38331720. Its totient is φ = 10794912.

The previous prime is 21746821. The next prime is 21746843. The reversal of 21746828 is 82864712.

It is a junction number, because it is equal to n+sod(n) for n = 21746791 and 21746800.

It is not an unprimeable number, because it can be changed into a prime (21746821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19001 + ... + 20112.

It is an arithmetic number, because the mean of its divisors is an integer number (3194310).

Almost surely, 2^21746828 is an apocalyptic number.

It is an amenable number.

21746828 is a deficient number, since it is larger than the sum of its proper divisors (16584892).

21746828 is a wasteful number, since it uses less digits than its factorization.

21746828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39256 (or 39254 counting only the distinct ones).

The product of its digits is 43008, while the sum is 38.

The square root of 21746828 is about 4663.3494400484. The cubic root of 21746828 is about 279.1249381554.

The spelling of 21746828 in words is "twenty-one million, seven hundred forty-six thousand, eight hundred twenty-eight".