28934721 has 24 divisors (see below), whose sum is σ = 43992000. Its totient is φ = 18299232.

The previous prime is 28934707. The next prime is 28934723. The reversal of 28934721 is 12743982.

It is not a de Polignac number, because 28934721 - 2¹⁵ = 28901953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28934723) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14460 + ... + 16338.

It is an arithmetic number, because the mean of its divisors is an integer number (1833000).

Almost surely, 2^28934721 is an apocalyptic number.

It is an amenable number.

28934721 is a deficient number, since it is larger than the sum of its proper divisors (15057279).

28934721 is a wasteful number, since it uses less digits than its factorization.

28934721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1973 (or 1970 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 28934721 is about 5379.1003894703. The cubic root of 28934721 is about 307.0009832080. Note that the first 3 decimals are identical.

The spelling of 28934721 in words is "twenty-eight million, nine hundred thirty-four thousand, seven hundred twenty-one".