28085664661 has 2 divisors, whose sum is σ = 28085664662. Its totient is φ = 28085664660.

The previous prime is 28085664643. The next prime is 28085664679. The reversal of 28085664661 is 16646658082.

It is a balanced prime because it is at equal distance from previous prime (28085664643) and next prime (28085664679).

It can be written as a sum of positive squares in only one way, i.e., 16274104900 + 11811559761 = 127570^2 + 108681^2 .

It is a cyclic number.

It is not a de Polignac number, because 28085664661 - 2²¹ = 28083567509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28085664599 and 28085664608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28085664631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14042832330 + 14042832331.

It is an arithmetic number, because the mean of its divisors is an integer number (14042832331).

Almost surely, 2^28085664661 is an apocalyptic number.

It is an amenable number.

28085664661 is a deficient number, since it is larger than the sum of its proper divisors (1).

28085664661 is an equidigital number, since it uses as much as digits as its factorization.

28085664661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3317760, while the sum is 52.

The spelling of 28085664661 in words is "twenty-eight billion, eighty-five million, six hundred sixty-four thousand, six hundred sixty-one".