28920018677761 has 4 divisors (see below), whose sum is σ = 28920162169300. Its totient is φ = 28919875186224.

The previous prime is 28920018677699. The next prime is 28920018677783. The reversal of 28920018677761 is 16777681002982.

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 19446821121025 + 9473197556736 = 4409855^2 + 3077856^2 .

It is a cyclic number.

It is not a de Polignac number, because 28920018677761 - 2²⁵ = 28919985123329 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28920018677693 and 28920018677702.

It is not an unprimeable number, because it can be changed into a prime (28920018677861) 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, 71443026 + ... + 71846683.

It is an arithmetic number, because the mean of its divisors is an integer number (7230040542325).

Almost surely, 2^{28920018677761} is an apocalyptic number.

It is an amenable number.

28920018677761 is a deficient number, since it is larger than the sum of its proper divisors (143491539).

28920018677761 is a wasteful number, since it uses less digits than its factorization.

28920018677761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143491538.

The product of its (nonzero) digits is 28449792, while the sum is 64.

The spelling of 28920018677761 in words is "twenty-eight trillion, nine hundred twenty billion, eighteen million, six hundred seventy-seven thousand, seven hundred sixty-one".