28461921 has 4 divisors (see below), whose sum is σ = 37949232. Its totient is φ = 18974612.

The previous prime is 28461911. The next prime is 28461959. The reversal of 28461921 is 12916482.

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 28461921 - 2⁵ = 28461889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28461911) 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, 4743651 + ... + 4743656.

It is an arithmetic number, because the mean of its divisors is an integer number (9487308).

Almost surely, 2^28461921 is an apocalyptic number.

It is an amenable number.

28461921 is a deficient number, since it is larger than the sum of its proper divisors (9487311).

28461921 is an equidigital number, since it uses as much as digits as its factorization.

28461921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9487310.

The product of its digits is 6912, while the sum is 33.

The square root of 28461921 is about 5334.9715088274. The cubic root of 28461921 is about 305.3196362420.

The spelling of 28461921 in words is "twenty-eight million, four hundred sixty-one thousand, nine hundred twenty-one".