28311521939 has 2 divisors, whose sum is σ = 28311521940. Its totient is φ = 28311521938.

The previous prime is 28311521923. The next prime is 28311522047. The reversal of 28311521939 is 93912511382.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28311521939 - 2⁴ = 28311521923 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28311521939.

It is not a weakly prime, because it can be changed into another prime (28311521639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14155760969 + 14155760970.

It is an arithmetic number, because the mean of its divisors is an integer number (14155760970).

Almost surely, 2^28311521939 is an apocalyptic number.

28311521939 is a deficient number, since it is larger than the sum of its proper divisors (1).

28311521939 is an equidigital number, since it uses as much as digits as its factorization.

28311521939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 116640, while the sum is 44.

The spelling of 28311521939 in words is "twenty-eight billion, three hundred eleven million, five hundred twenty-one thousand, nine hundred thirty-nine".