28929947 has 4 divisors (see below), whose sum is σ = 28960536. Its totient is φ = 28899360.

The previous prime is 28929889. The next prime is 28929977. The reversal of 28929947 is 74992982.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74992982 = 2 ⋅37496491.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28929947 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28929895 and 28929904.

It is not an unprimeable number, because it can be changed into a prime (28929977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13829 + ... + 15782.

It is an arithmetic number, because the mean of its divisors is an integer number (7240134).

Almost surely, 2^28929947 is an apocalyptic number.

28929947 is a deficient number, since it is larger than the sum of its proper divisors (30589).

28929947 is an equidigital number, since it uses as much as digits as its factorization.

28929947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30588.

The product of its digits is 653184, while the sum is 50.

The square root of 28929947 is about 5378.6566166655. The cubic root of 28929947 is about 306.9840980350.

The spelling of 28929947 in words is "twenty-eight million, nine hundred twenty-nine thousand, nine hundred forty-seven".