21828929 has 8 divisors (see below), whose sum is σ = 23719680. Its totient is φ = 20012400.

The previous prime is 21828913. The next prime is 21828931. The reversal of 21828929 is 92982812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21828929 - 2⁴ = 21828913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21828949) 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, 17942 + ... + 19119.

It is an arithmetic number, because the mean of its divisors is an integer number (2964960).

Almost surely, 2^21828929 is an apocalyptic number.

It is an amenable number.

21828929 is a deficient number, since it is larger than the sum of its proper divisors (1890751).

21828929 is a wasteful number, since it uses less digits than its factorization.

21828929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37111.

The product of its digits is 41472, while the sum is 41.

The square root of 21828929 is about 4672.1439404196. The cubic root of 21828929 is about 279.4757580237.

It can be divided in two parts, 2182 and 8929, that added together give a palindrome (11111).

The spelling of 21828929 in words is "twenty-one million, eight hundred twenty-eight thousand, nine hundred twenty-nine".