28029947 has 4 divisors (see below), whose sum is σ = 30578136. Its totient is φ = 25481760.

The previous prime is 28029943. The next prime is 28029961. The reversal of 28029947 is 74992082.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28029947 - 2² = 28029943 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28029941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1274078 + ... + 1274099.

It is an arithmetic number, because the mean of its divisors is an integer number (7644534).

Almost surely, 2^28029947 is an apocalyptic number.

28029947 is a deficient number, since it is larger than the sum of its proper divisors (2548189).

28029947 is a wasteful number, since it uses less digits than its factorization.

28029947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2548188.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 28029947 is about 5294.3315914287. The cubic root of 28029947 is about 303.7671166270.

The spelling of 28029947 in words is "twenty-eight million, twenty-nine thousand, nine hundred forty-seven".