28720029 has 24 divisors (see below), whose sum is σ = 42614112. Its totient is φ = 17184960.

The previous prime is 28719989. The next prime is 28720037. The reversal of 28720029 is 92002782.

It is not a de Polignac number, because 28720029 - 2¹⁷ = 28588957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28719978 and 28720005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28720099) 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, 17994 + ... + 19524.

It is an arithmetic number, because the mean of its divisors is an integer number (1775588).

Almost surely, 2^28720029 is an apocalyptic number.

It is an amenable number.

28720029 is a deficient number, since it is larger than the sum of its proper divisors (13894083).

28720029 is a wasteful number, since it uses less digits than its factorization.

28720029 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1597 (or 1584 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 28720029 is about 5359.1071084650. The cubic root of 28720029 is about 306.2397945232.

The spelling of 28720029 in words is "twenty-eight million, seven hundred twenty thousand, twenty-nine".