28728385649 has 2 divisors, whose sum is σ = 28728385650. Its totient is φ = 28728385648.

The previous prime is 28728385619. The next prime is 28728385657. The reversal of 28728385649 is 94658382782.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 26918308624 + 1810077025 = 164068^2 + 42545^2 .

It is a cyclic number.

It is not a de Polignac number, because 28728385649 - 2²⁰ = 28727337073 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28728385591 and 28728385600.

It is not a weakly prime, because it can be changed into another prime (28728385619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14364192824 + 14364192825.

It is an arithmetic number, because the mean of its divisors is an integer number (14364192825).

Almost surely, 2^28728385649 is an apocalyptic number.

It is an amenable number.

28728385649 is a deficient number, since it is larger than the sum of its proper divisors (1).

28728385649 is an equidigital number, since it uses as much as digits as its factorization.

28728385649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46448640, while the sum is 62.

The spelling of 28728385649 in words is "twenty-eight billion, seven hundred twenty-eight million, three hundred eighty-five thousand, six hundred forty-nine".