28745421 has 8 divisors (see below), whose sum is σ = 38386080. Its totient is φ = 19134192.

The previous prime is 28745407. The next prime is 28745441. The reversal of 28745421 is 12454782.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28745421 - 2⁵ = 28745389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28745441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4966 + ... + 9063.

It is an arithmetic number, because the mean of its divisors is an integer number (4798260).

Almost surely, 2^28745421 is an apocalyptic number.

It is an amenable number.

28745421 is a deficient number, since it is larger than the sum of its proper divisors (9640659).

28745421 is a wasteful number, since it uses less digits than its factorization.

28745421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14715.

The product of its digits is 17920, while the sum is 33.

The square root of 28745421 is about 5361.4756364270. The cubic root of 28745421 is about 306.3300190181.

The spelling of 28745421 in words is "twenty-eight million, seven hundred forty-five thousand, four hundred twenty-one".