28139941 has 2 divisors, whose sum is σ = 28139942. Its totient is φ = 28139940.

The previous prime is 28139939. The next prime is 28139957. The reversal of 28139941 is 14993182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22752900 + 5387041 = 4770^2 + 2321^2 .

It is a cyclic number.

It is not a de Polignac number, because 28139941 - 2¹ = 28139939 is a prime.

Together with 28139939, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 28139941.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28139911) 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, 14069970 + 14069971.

It is an arithmetic number, because the mean of its divisors is an integer number (14069971).

Almost surely, 2^28139941 is an apocalyptic number.

It is an amenable number.

28139941 is a deficient number, since it is larger than the sum of its proper divisors (1).

28139941 is an equidigital number, since it uses as much as digits as its factorization.

28139941 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 37.

The square root of 28139941 is about 5304.7093228564. The cubic root of 28139941 is about 304.1639416115.

The spelling of 28139941 in words is "twenty-eight million, one hundred thirty-nine thousand, nine hundred forty-one".