28139977 has 2 divisors, whose sum is σ = 28139978. Its totient is φ = 28139976.

The previous prime is 28139963. The next prime is 28139983. The reversal of 28139977 is 77993182.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17505856 + 10634121 = 4184^2 + 3261^2 .

It is a cyclic number.

It is not a de Polignac number, because 28139977 - 2¹⁹ = 27615689 is a prime.

It is not a weakly prime, because it can be changed into another prime (28139957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14069988 + 14069989.

It is an arithmetic number, because the mean of its divisors is an integer number (14069989).

Almost surely, 2^28139977 is an apocalyptic number.

It is an amenable number.

28139977 is a deficient number, since it is larger than the sum of its proper divisors (1).

28139977 is an equidigital number, since it uses as much as digits as its factorization.

28139977 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 190512, while the sum is 46.

The square root of 28139977 is about 5304.7127160667. The cubic root of 28139977 is about 304.1640713192.

The spelling of 28139977 in words is "twenty-eight million, one hundred thirty-nine thousand, nine hundred seventy-seven".