28722993 has 16 divisors (see below), whose sum is σ = 41514816. Its totient is φ = 17559360.

The previous prime is 28722983. The next prime is 28722997. The reversal of 28722993 is 39922782.

It is not a de Polignac number, because 28722993 - 2¹² = 28718897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28722997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3778 + ... + 8468.

It is an arithmetic number, because the mean of its divisors is an integer number (2594676).

Almost surely, 2^28722993 is an apocalyptic number.

It is an amenable number.

28722993 is a deficient number, since it is larger than the sum of its proper divisors (12791823).

28722993 is a wasteful number, since it uses less digits than its factorization.

28722993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4864.

The product of its digits is 108864, while the sum is 42.

The square root of 28722993 is about 5359.3836399347. The cubic root of 28722993 is about 306.2503291403.

The spelling of 28722993 in words is "twenty-eight million, seven hundred twenty-two thousand, nine hundred ninety-three".