28297278 has 24 divisors (see below), whose sum is σ = 61547616. Its totient is φ = 9396000.

The previous prime is 28297261. The next prime is 28297279. The reversal of 28297278 is 87279282.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28297279) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1978 + ... + 7778.

It is an arithmetic number, because the mean of its divisors is an integer number (2564484).

Almost surely, 2^28297278 is an apocalyptic number.

28297278 is an abundant number, since it is smaller than the sum of its proper divisors (33250338).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28297278 is a wasteful number, since it uses less digits than its factorization.

28297278 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6080 (or 6077 counting only the distinct ones).

The product of its digits is 225792, while the sum is 45.

The square root of 28297278 is about 5319.5185872408. The cubic root of 28297278 is about 304.7297722966.

The spelling of 28297278 in words is "twenty-eight million, two hundred ninety-seven thousand, two hundred seventy-eight".