28117557617761 has 4 divisors (see below), whose sum is σ = 28117643742724. Its totient is φ = 28117471492800.

The previous prime is 28117557617749. The next prime is 28117557617777. The reversal of 28117557617761 is 16771675571182.

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 11196519054400 + 16921038563361 = 3346120^2 + 4113519^2 .

It is a cyclic number.

It is not a de Polignac number, because 28117557617761 - 2¹⁹ = 28117557093473 is a prime.

It is a super-3 number, since 3×28117557617761³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28117557617693 and 28117557617702.

It is not an unprimeable number, because it can be changed into a prime (28117557617701) 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, 42570900 + ... + 43226341.

It is an arithmetic number, because the mean of its divisors is an integer number (7029410935681).

Almost surely, 2^{28117557617761} is an apocalyptic number.

It is an amenable number.

28117557617761 is a deficient number, since it is larger than the sum of its proper divisors (86124963).

28117557617761 is an equidigital number, since it uses as much as digits as its factorization.

28117557617761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86124962.

The product of its digits is 34574400, while the sum is 64.

The spelling of 28117557617761 in words is "twenty-eight trillion, one hundred seventeen billion, five hundred fifty-seven million, six hundred seventeen thousand, seven hundred sixty-one".