28506121939 has 2 divisors, whose sum is σ = 28506121940. Its totient is φ = 28506121938.

The previous prime is 28506121927. The next prime is 28506121979. The reversal of 28506121939 is 93912160582.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28506121939 - 2⁵ = 28506121907 is a prime.

It is a super-2 number, since 2×28506121939² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28506121979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14253060969 + 14253060970.

It is an arithmetic number, because the mean of its divisors is an integer number (14253060970).

Almost surely, 2^28506121939 is an apocalyptic number.

28506121939 is a deficient number, since it is larger than the sum of its proper divisors (1).

28506121939 is an equidigital number, since it uses as much as digits as its factorization.

28506121939 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 233280, while the sum is 46.

The spelling of 28506121939 in words is "twenty-eight billion, five hundred six million, one hundred twenty-one thousand, nine hundred thirty-nine".