28925021 has 4 divisors (see below), whose sum is σ = 29052672. Its totient is φ = 28797372.

The previous prime is 28924997. The next prime is 28925027. The reversal of 28925021 is 12052982.

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.

It is a cyclic number.

It is not a de Polignac number, because 28925021 - 2⁶ = 28924957 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 (28925027) 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, 63485 + ... + 63938.

It is an arithmetic number, because the mean of its divisors is an integer number (7263168).

Almost surely, 2^28925021 is an apocalyptic number.

It is an amenable number.

28925021 is a deficient number, since it is larger than the sum of its proper divisors (127651).

28925021 is a wasteful number, since it uses less digits than its factorization.

28925021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127650.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 28925021 is about 5378.1986761368. The cubic root of 28925021 is about 306.9666733055.

The spelling of 28925021 in words is "twenty-eight million, nine hundred twenty-five thousand, twenty-one".