28067021 has 4 divisors (see below), whose sum is σ = 28224000. Its totient is φ = 27910044.

The previous prime is 28066993. The next prime is 28067027. The reversal of 28067021 is 12076082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12076082 = 2 ⋅6038041.

It is a cyclic number.

It is not a de Polignac number, because 28067021 - 2⁶ = 28066957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28067027) 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, 78221 + ... + 78578.

It is an arithmetic number, because the mean of its divisors is an integer number (7056000).

Almost surely, 2^28067021 is an apocalyptic number.

It is an amenable number.

28067021 is a deficient number, since it is larger than the sum of its proper divisors (156979).

28067021 is a wasteful number, since it uses less digits than its factorization.

28067021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156978.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 28067021 is about 5297.8317262820. The cubic root of 28067021 is about 303.9009841716.

The spelling of 28067021 in words is "twenty-eight million, sixty-seven thousand, twenty-one".