28032021 has 16 divisors (see below), whose sum is σ = 42235200. Its totient is φ = 18370224.

The previous prime is 28032019. The next prime is 28032041. The reversal of 28032021 is 12023082.

It is a happy number.

It is not a de Polignac number, because 28032021 - 2¹ = 28032019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28031985 and 28032003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28032041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7206 + ... + 10391.

It is an arithmetic number, because the mean of its divisors is an integer number (2639700).

Almost surely, 2^28032021 is an apocalyptic number.

It is an amenable number.

28032021 is a deficient number, since it is larger than the sum of its proper divisors (14203179).

28032021 is a wasteful number, since it uses less digits than its factorization.

28032021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17665 (or 17659 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 28032021 is about 5294.5274576680. The cubic root of 28032021 is about 303.7746085839.

The spelling of 28032021 in words is "twenty-eight million, thirty-two thousand, twenty-one".