21943028 has 6 divisors (see below), whose sum is σ = 38400306. Its totient is φ = 10971512.

The previous prime is 21943027. The next prime is 21943037. The reversal of 21943028 is 82034912.

It can be written as a sum of positive squares in only one way, i.e., 21921124 + 21904 = 4682^2 + 148^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21943021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2742875 + ... + 2742882.

It is an arithmetic number, because the mean of its divisors is an integer number (6400051).

Almost surely, 2^21943028 is an apocalyptic number.

It is an amenable number.

21943028 is a deficient number, since it is larger than the sum of its proper divisors (16457278).

21943028 is a wasteful number, since it uses less digits than its factorization.

21943028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5485761 (or 5485759 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 21943028 is about 4684.3385872501. The cubic root of 21943028 is about 279.9618485434.

The spelling of 21943028 in words is "twenty-one million, nine hundred forty-three thousand, twenty-eight".