28067921 has 16 divisors (see below), whose sum is σ = 33945600. Its totient is φ = 22670928.

The previous prime is 28067891. The next prime is 28067939. The reversal of 28067921 is 12976082.

It is a happy number.

It is not a de Polignac number, because 28067921 - 2¹⁴ = 28051537 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28067951) 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, 31346 + ... + 32228.

It is an arithmetic number, because the mean of its divisors is an integer number (2121600).

Almost surely, 2^28067921 is an apocalyptic number.

It is an amenable number.

28067921 is a deficient number, since it is larger than the sum of its proper divisors (5877679).

28067921 is a wasteful number, since it uses less digits than its factorization.

28067921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1148.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 28067921 is about 5297.9166660113. The cubic root of 28067921 is about 303.9042324437.

The spelling of 28067921 in words is "twenty-eight million, sixty-seven thousand, nine hundred twenty-one".