28904137 has 4 divisors (see below), whose sum is σ = 29031696. Its totient is φ = 28776580.

The previous prime is 28904129. The next prime is 28904147. The reversal of 28904137 is 73140982.

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: 73140982 = 2 ⋅36570491.

It is a cyclic number.

It is not a de Polignac number, because 28904137 - 2³ = 28904129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28904147) 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, 63439 + ... + 63892.

It is an arithmetic number, because the mean of its divisors is an integer number (7257924).

Almost surely, 2^28904137 is an apocalyptic number.

It is an amenable number.

28904137 is a deficient number, since it is larger than the sum of its proper divisors (127559).

28904137 is a wasteful number, since it uses less digits than its factorization.

28904137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127558.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 28904137 is about 5376.2567833019. The cubic root of 28904137 is about 306.8927783955.

The spelling of 28904137 in words is "twenty-eight million, nine hundred four thousand, one hundred thirty-seven".