28304077421 has 2 divisors, whose sum is σ = 28304077422. Its totient is φ = 28304077420.

The previous prime is 28304077327. The next prime is 28304077447. The reversal of 28304077421 is 12477040382.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15327678025 + 12976399396 = 123805^2 + 113914^2 .

It is a cyclic number.

It is not a de Polignac number, because 28304077421 - 2¹⁰ = 28304076397 is a prime.

It is a super-2 number, since 2×28304077421² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28304077721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14152038710 + 14152038711.

It is an arithmetic number, because the mean of its divisors is an integer number (14152038711).

Almost surely, 2^28304077421 is an apocalyptic number.

It is an amenable number.

28304077421 is a deficient number, since it is larger than the sum of its proper divisors (1).

28304077421 is an equidigital number, since it uses as much as digits as its factorization.

28304077421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75264, while the sum is 38.

The spelling of 28304077421 in words is "twenty-eight billion, three hundred four million, seventy-seven thousand, four hundred twenty-one".