28721946 has 16 divisors (see below), whose sum is σ = 62666208. Its totient is φ = 8703600.

The previous prime is 28721933. The next prime is 28721971. The reversal of 28721946 is 64912782.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 217525 + ... + 217656.

It is an arithmetic number, because the mean of its divisors is an integer number (3916638).

Almost surely, 2^28721946 is an apocalyptic number.

28721946 is an abundant number, since it is smaller than the sum of its proper divisors (33944262).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28721946 is a wasteful number, since it uses less digits than its factorization.

28721946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435197.

The product of its digits is 48384, while the sum is 39.

The square root of 28721946 is about 5359.2859599017. The cubic root of 28721946 is about 306.2466079869.

The spelling of 28721946 in words is "twenty-eight million, seven hundred twenty-one thousand, nine hundred forty-six".