28994143 has 4 divisors (see below), whose sum is σ = 29131768. Its totient is φ = 28856520.

The previous prime is 28994123. The next prime is 28994177. The reversal of 28994143 is 34149982.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28994143 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28994096 and 28994105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28994123) 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, 68496 + ... + 68917.

It is an arithmetic number, because the mean of its divisors is an integer number (7282942).

Almost surely, 2^28994143 is an apocalyptic number.

28994143 is a deficient number, since it is larger than the sum of its proper divisors (137625).

28994143 is a wasteful number, since it uses less digits than its factorization.

28994143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137624.

The product of its digits is 62208, while the sum is 40.

The square root of 28994143 is about 5384.6209708762. The cubic root of 28994143 is about 307.2109977741.

The spelling of 28994143 in words is "twenty-eight million, nine hundred ninety-four thousand, one hundred forty-three".