28972945 has 8 divisors (see below), whose sum is σ = 34796520. Its totient is φ = 23159040.

The previous prime is 28972919. The next prime is 28972969. The reversal of 28972945 is 54927982.

It can be written as a sum of positive squares in 4 ways, for example, as 4460544 + 24512401 = 2112^2 + 4951^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28972945 - 2¹⁹ = 28448657 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28972895 and 28972904.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 9801 + ... + 12409.

It is an arithmetic number, because the mean of its divisors is an integer number (4349565).

Almost surely, 2^28972945 is an apocalyptic number.

It is an amenable number.

28972945 is a deficient number, since it is larger than the sum of its proper divisors (5823575).

28972945 is a wasteful number, since it uses less digits than its factorization.

28972945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4835.

The product of its digits is 362880, while the sum is 46.

The square root of 28972945 is about 5382.6522272946. The cubic root of 28972945 is about 307.1361108513.

The spelling of 28972945 in words is "twenty-eight million, nine hundred seventy-two thousand, nine hundred forty-five".