28031137 has 4 divisors (see below), whose sum is σ = 29506480. Its totient is φ = 26555796.

The previous prime is 28031131. The next prime is 28031149. The reversal of 28031137 is 73113082.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28031137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28031131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 737643 + ... + 737680.

It is an arithmetic number, because the mean of its divisors is an integer number (7376620).

Almost surely, 2^28031137 is an apocalyptic number.

It is an amenable number.

28031137 is a deficient number, since it is larger than the sum of its proper divisors (1475343).

28031137 is a wasteful number, since it uses less digits than its factorization.

28031137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1475342.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 28031137 is about 5294.4439745832. The cubic root of 28031137 is about 303.7714153360.

The spelling of 28031137 in words is "twenty-eight million, thirty-one thousand, one hundred thirty-seven".