28313939 has 2 divisors, whose sum is σ = 28313940. Its totient is φ = 28313938.

The previous prime is 28313921. The next prime is 28313941. The reversal of 28313939 is 93931382.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28313939 - 2¹² = 28309843 is a prime.

Together with 28313941, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28313969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14156969 + 14156970.

It is an arithmetic number, because the mean of its divisors is an integer number (14156970).

Almost surely, 2^28313939 is an apocalyptic number.

28313939 is a deficient number, since it is larger than the sum of its proper divisors (1).

28313939 is an equidigital number, since it uses as much as digits as its factorization.

28313939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34992, while the sum is 38.

The square root of 28313939 is about 5321.0843819658. The cubic root of 28313939 is about 304.7895672896.

The spelling of 28313939 in words is "twenty-eight million, three hundred thirteen thousand, nine hundred thirty-nine".