28135661 has 2 divisors, whose sum is σ = 28135662. Its totient is φ = 28135660.

The previous prime is 28135649. The next prime is 28135673. The reversal of 28135661 is 16653182.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (28135649) and next prime (28135673).

It can be written as a sum of positive squares in only one way, i.e., 21855625 + 6280036 = 4675^2 + 2506^2 .

It is a cyclic number.

It is not a de Polignac number, because 28135661 - 2¹⁰ = 28134637 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28135691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14067830 + 14067831.

It is an arithmetic number, because the mean of its divisors is an integer number (14067831).

Almost surely, 2^28135661 is an apocalyptic number.

It is an amenable number.

28135661 is a deficient number, since it is larger than the sum of its proper divisors (1).

28135661 is an equidigital number, since it uses as much as digits as its factorization.

28135661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 32.

The square root of 28135661 is about 5304.3058923859. The cubic root of 28135661 is about 304.1485200241.

The spelling of 28135661 in words is "twenty-eight million, one hundred thirty-five thousand, six hundred sixty-one".