28542121 has 4 divisors (see below), whose sum is σ = 28747600. Its totient is φ = 28336644.

The previous prime is 28542089. The next prime is 28542131. The reversal of 28542121 is 12124582.

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: 12124582 = 2 ⋅6062291.

It is a cyclic number.

It is not a de Polignac number, because 28542121 - 2⁵ = 28542089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28542131) 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, 102531 + ... + 102808.

It is an arithmetic number, because the mean of its divisors is an integer number (7186900).

Almost surely, 2^28542121 is an apocalyptic number.

It is an amenable number.

28542121 is a deficient number, since it is larger than the sum of its proper divisors (205479).

28542121 is a wasteful number, since it uses less digits than its factorization.

28542121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205478.

The product of its digits is 1280, while the sum is 25.

The square root of 28542121 is about 5342.4826625830. The cubic root of 28542121 is about 305.6061438567.

The spelling of 28542121 in words is "twenty-eight million, five hundred forty-two thousand, one hundred twenty-one".