28055555617 has 4 divisors (see below), whose sum is σ = 29705882436. Its totient is φ = 26405228800.

The previous prime is 28055555611. The next prime is 28055555681. The reversal of 28055555617 is 71655555082.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25024392481 + 3031163136 = 158191^2 + 55056^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28055555617 is a prime.

It is a super-2 number, since 2×28055555617² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28055555611) 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, 825163384 + ... + 825163417.

It is an arithmetic number, because the mean of its divisors is an integer number (7426470609).

Almost surely, 2^28055555617 is an apocalyptic number.

It is an amenable number.

28055555617 is a deficient number, since it is larger than the sum of its proper divisors (1650326819).

28055555617 is a wasteful number, since it uses less digits than its factorization.

28055555617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1650326818.

The product of its (nonzero) digits is 2100000, while the sum is 49.

The spelling of 28055555617 in words is "twenty-eight billion, fifty-five million, five hundred fifty-five thousand, six hundred seventeen".