28278537 has 24 divisors (see below), whose sum is σ = 44804736. Its totient is φ = 15811488.

The previous prime is 28278533. The next prime is 28278559. The reversal of 28278537 is 73587282.

It is not a de Polignac number, because 28278537 - 2² = 28278533 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28278533) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4863 + ... + 8955.

It is an arithmetic number, because the mean of its divisors is an integer number (1866864).

Almost surely, 2^28278537 is an apocalyptic number.

It is an amenable number.

28278537 is a deficient number, since it is larger than the sum of its proper divisors (16526199).

28278537 is a wasteful number, since it uses less digits than its factorization.

28278537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4157 (or 4150 counting only the distinct ones).

The product of its digits is 188160, while the sum is 42.

The square root of 28278537 is about 5317.7567638996. The cubic root of 28278537 is about 304.6624842947.

The spelling of 28278537 in words is "twenty-eight million, two hundred seventy-eight thousand, five hundred thirty-seven".