28642661 has 2 divisors, whose sum is σ = 28642662. Its totient is φ = 28642660.

The previous prime is 28642657. The next prime is 28642681. The reversal of 28642661 is 16624682.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28026436 + 616225 = 5294^2 + 785^2 .

It is a cyclic number.

It is not a de Polignac number, because 28642661 - 2² = 28642657 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 (28642681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14321330 + 14321331.

It is an arithmetic number, because the mean of its divisors is an integer number (14321331).

Almost surely, 2^28642661 is an apocalyptic number.

It is an amenable number.

28642661 is a deficient number, since it is larger than the sum of its proper divisors (1).

28642661 is an equidigital number, since it uses as much as digits as its factorization.

28642661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27648, while the sum is 35.

The square root of 28642661 is about 5351.8838739270. The cubic root of 28642661 is about 305.9645572460.

The spelling of 28642661 in words is "twenty-eight million, six hundred forty-two thousand, six hundred sixty-one".