28397808907 has 4 divisors (see below), whose sum is σ = 30582255760. Its totient is φ = 26213362056.

The previous prime is 28397808863. The next prime is 28397808953. The reversal of 28397808907 is 70980879382.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28397808907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28397838907) 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, 1092223407 + ... + 1092223432.

It is an arithmetic number, because the mean of its divisors is an integer number (7645563940).

Almost surely, 2^28397808907 is an apocalyptic number.

28397808907 is a deficient number, since it is larger than the sum of its proper divisors (2184446853).

28397808907 is a wasteful number, since it uses less digits than its factorization.

28397808907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2184446852.

The product of its (nonzero) digits is 12192768, while the sum is 61.

The spelling of 28397808907 in words is "twenty-eight billion, three hundred ninety-seven million, eight hundred eight thousand, nine hundred seven".