28351386647257 has 4 divisors (see below), whose sum is σ = 28351435344336. Its totient is φ = 28351337950180.

The previous prime is 28351386647239. The next prime is 28351386647293. The reversal of 28351386647257 is 75274668315382.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28351386647257 - 2¹⁵ = 28351386614489 is a prime.

It is a super-2 number, since 2×28351386647257² (a number of 28 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (67) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28351386647192 and 28351386647201.

It is not an unprimeable number, because it can be changed into a prime (28351386647057) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23464543 + ... + 24643204.

It is an arithmetic number, because the mean of its divisors is an integer number (7087858836084).

Almost surely, 2^{28351386647257} is an apocalyptic number.

It is an amenable number.

28351386647257 is a deficient number, since it is larger than the sum of its proper divisors (48697079).

28351386647257 is an equidigital number, since it uses as much as digits as its factorization.

28351386647257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48697078.

The product of its digits is 406425600, while the sum is 67.

The spelling of 28351386647257 in words is "twenty-eight trillion, three hundred fifty-one billion, three hundred eighty-six million, six hundred forty-seven thousand, two hundred fifty-seven".