28142501 has 4 divisors (see below), whose sum is σ = 29366112. Its totient is φ = 26918892.

The previous prime is 28142467. The next prime is 28142503. The reversal of 28142501 is 10524182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10524182 = 2 ⋅5262091.

It is a cyclic number.

It is not a de Polignac number, because 28142501 - 2⁶ = 28142437 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 1223587 = 28142501 / (2 + 8 + 1 + 4 + 2 + 5 + 0 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28142503) 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, 611771 + ... + 611816.

It is an arithmetic number, because the mean of its divisors is an integer number (7341528).

Almost surely, 2^28142501 is an apocalyptic number.

It is an amenable number.

28142501 is a deficient number, since it is larger than the sum of its proper divisors (1223611).

28142501 is a wasteful number, since it uses less digits than its factorization.

28142501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1223610.

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 28142501 is about 5304.9506123997. The cubic root of 28142501 is about 304.1731649912.

Adding to 28142501 its reverse (10524182), we get a palindrome (38666683).

The spelling of 28142501 in words is "twenty-eight million, one hundred forty-two thousand, five hundred one".