28205444761 has 4 divisors (see below), whose sum is σ = 30375094372. Its totient is φ = 26035795152.

The previous prime is 28205444741. The next prime is 28205444779. The reversal of 28205444761 is 16744450282.

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 18654096400 + 9551348361 = 136580^2 + 97731^2 .

It is a cyclic number.

It is not a de Polignac number, because 28205444761 - 2²¹ = 28203347609 is a prime.

It is a super-2 number, since 2×28205444761² (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 (28205444711) 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, 1084824786 + ... + 1084824811.

It is an arithmetic number, because the mean of its divisors is an integer number (7593773593).

Almost surely, 2^28205444761 is an apocalyptic number.

It is an amenable number.

28205444761 is a deficient number, since it is larger than the sum of its proper divisors (2169649611).

28205444761 is a wasteful number, since it uses less digits than its factorization.

28205444761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2169649610.

The product of its (nonzero) digits is 430080, while the sum is 43.

The spelling of 28205444761 in words is "twenty-eight billion, two hundred five million, four hundred forty-four thousand, seven hundred sixty-one".