28057728449 has 2 divisors, whose sum is σ = 28057728450. Its totient is φ = 28057728448.

The previous prime is 28057728409. The next prime is 28057728467. The reversal of 28057728449 is 94482775082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22256164225 + 5801564224 = 149185^2 + 76168^2 .

It is a cyclic number.

It is not a de Polignac number, because 28057728449 - 2¹² = 28057724353 is a prime.

It is a super-2 number, since 2×28057728449² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28057728394 and 28057728403.

It is not a weakly prime, because it can be changed into another prime (28057728409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14028864224 + 14028864225.

It is an arithmetic number, because the mean of its divisors is an integer number (14028864225).

Almost surely, 2^28057728449 is an apocalyptic number.

It is an amenable number.

28057728449 is a deficient number, since it is larger than the sum of its proper divisors (1).

28057728449 is an equidigital number, since it uses as much as digits as its factorization.

28057728449 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9031680, while the sum is 56.

The spelling of 28057728449 in words is "twenty-eight billion, fifty-seven million, seven hundred twenty-eight thousand, four hundred forty-nine".