28143923 has 4 divisors (see below), whose sum is σ = 28261920. Its totient is φ = 28025928.

The previous prime is 28143911. The next prime is 28143943. The reversal of 28143923 is 32934182.

It is a happy number.

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 28143923 - 2¹⁶ = 28078387 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28143923.

It is not an unprimeable number, because it can be changed into a prime (28143943) 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, 58640 + ... + 59117.

It is an arithmetic number, because the mean of its divisors is an integer number (7065480).

Almost surely, 2^28143923 is an apocalyptic number.

28143923 is a deficient number, since it is larger than the sum of its proper divisors (117997).

28143923 is a wasteful number, since it uses less digits than its factorization.

28143923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117996.

The product of its digits is 10368, while the sum is 32.

The square root of 28143923 is about 5305.0846364596. The cubic root of 28143923 is about 304.1782880487.

The spelling of 28143923 in words is "twenty-eight million, one hundred forty-three thousand, nine hundred twenty-three".