28765661 has 2 divisors, whose sum is σ = 28765662. Its totient is φ = 28765660.

The previous prime is 28765657. The next prime is 28765669. The reversal of 28765661 is 16656782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25060036 + 3705625 = 5006^2 + 1925^2 .

It is a cyclic number.

It is not a de Polignac number, because 28765661 - 2² = 28765657 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28765669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14382830 + 14382831.

It is an arithmetic number, because the mean of its divisors is an integer number (14382831).

Almost surely, 2^28765661 is an apocalyptic number.

It is an amenable number.

28765661 is a deficient number, since it is larger than the sum of its proper divisors (1).

28765661 is an equidigital number, since it uses as much as digits as its factorization.

28765661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 120960, while the sum is 41.

The square root of 28765661 is about 5363.3628443356. The cubic root of 28765661 is about 306.4018990456.

The spelling of 28765661 in words is "twenty-eight million, seven hundred sixty-five thousand, six hundred sixty-one".