28991968 has 12 divisors (see below), whose sum is σ = 57078000. Its totient is φ = 14495968.

The previous prime is 28991947. The next prime is 28991969. The reversal of 28991968 is 86919982.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28991969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 452968 + ... + 453031.

It is an arithmetic number, because the mean of its divisors is an integer number (4756500).

Almost surely, 2^28991968 is an apocalyptic number.

It is an amenable number.

28991968 is a deficient number, since it is larger than the sum of its proper divisors (28086032).

28991968 is an equidigital number, since it uses as much as digits as its factorization.

28991968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 906009 (or 906001 counting only the distinct ones).

The product of its digits is 559872, while the sum is 52.

The square root of 28991968 is about 5384.4190030123. The cubic root of 28991968 is about 307.2033157556.

The spelling of 28991968 in words is "twenty-eight million, nine hundred ninety-one thousand, nine hundred sixty-eight".