21833428 has 6 divisors (see below), whose sum is σ = 38208506. Its totient is φ = 10916712.

The previous prime is 21833411. The next prime is 21833431. The reversal of 21833428 is 82433812.

It can be written as a sum of positive squares in only one way, i.e., 18215824 + 3617604 = 4268^2 + 1902^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21833428.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2729175 + ... + 2729182.

Almost surely, 2^21833428 is an apocalyptic number.

It is an amenable number.

21833428 is a deficient number, since it is larger than the sum of its proper divisors (16375078).

21833428 is a wasteful number, since it uses less digits than its factorization.

21833428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5458361 (or 5458359 counting only the distinct ones).

The product of its digits is 9216, while the sum is 31.

The square root of 21833428 is about 4672.6253862256. The cubic root of 21833428 is about 279.4949569357.

The spelling of 21833428 in words is "twenty-one million, eight hundred thirty-three thousand, four hundred twenty-eight".