28373021 has 4 divisors (see below), whose sum is σ = 28654044. Its totient is φ = 28092000.

The previous prime is 28373003. The next prime is 28373039. The reversal of 28373021 is 12037382.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (28373003) and next prime (28373039).

It can be written as a sum of positive squares in 2 ways, for example, as 12460900 + 15912121 = 3530^2 + 3989^2 .

It is a cyclic number.

It is not a de Polignac number, because 28373021 - 2²² = 24178717 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 (28373071) 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, 140360 + ... + 140561.

It is an arithmetic number, because the mean of its divisors is an integer number (7163511).

Almost surely, 2^28373021 is an apocalyptic number.

It is an amenable number.

28373021 is a deficient number, since it is larger than the sum of its proper divisors (281023).

28373021 is a wasteful number, since it uses less digits than its factorization.

28373021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281022.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 28373021 is about 5326.6331767825. The cubic root of 28373021 is about 305.0014189668.

The spelling of 28373021 in words is "twenty-eight million, three hundred seventy-three thousand, twenty-one".