28139807 has 2 divisors, whose sum is σ = 28139808. Its totient is φ = 28139806.

The previous prime is 28139789. The next prime is 28139819. The reversal of 28139807 is 70893182.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28139807 - 2¹⁶ = 28074271 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28139857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14069903 + 14069904.

It is an arithmetic number, because the mean of its divisors is an integer number (14069904).

Almost surely, 2^28139807 is an apocalyptic number.

28139807 is a deficient number, since it is larger than the sum of its proper divisors (1).

28139807 is an equidigital number, since it uses as much as digits as its factorization.

28139807 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 28139807 is about 5304.6966925546. The cubic root of 28139807 is about 304.1634588098.

The spelling of 28139807 in words is "twenty-eight million, one hundred thirty-nine thousand, eight hundred seven".