28731807 has 32 divisors (see below), whose sum is σ = 47846400. Its totient is φ = 16907616.

The previous prime is 28731803. The next prime is 28731809. The reversal of 28731807 is 70813782.

It is not a de Polignac number, because 28731807 - 2² = 28731803 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28731803) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6294 + ... + 9852.

It is an arithmetic number, because the mean of its divisors is an integer number (1495200).

Almost surely, 2^28731807 is an apocalyptic number.

28731807 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

28731807 is a deficient number, since it is larger than the sum of its proper divisors (19114593).

28731807 is a wasteful number, since it uses less digits than its factorization.

28731807 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3604 (or 3598 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 28731807 is about 5360.2058729120. The cubic root of 28731807 is about 306.2816514836.

The spelling of 28731807 in words is "twenty-eight million, seven hundred thirty-one thousand, eight hundred seven".