28981661 has 2 divisors, whose sum is σ = 28981662. Its totient is φ = 28981660.

The previous prime is 28981637. The next prime is 28981697. The reversal of 28981661 is 16618982.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24700900 + 4280761 = 4970^2 + 2069^2 .

It is a cyclic number.

It is not a de Polignac number, because 28981661 - 2⁶ = 28981597 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 (28980661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14490830 + 14490831.

It is an arithmetic number, because the mean of its divisors is an integer number (14490831).

Almost surely, 2^28981661 is an apocalyptic number.

It is an amenable number.

28981661 is a deficient number, since it is larger than the sum of its proper divisors (1).

28981661 is an equidigital number, since it uses as much as digits as its factorization.

28981661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 41.

The square root of 28981661 is about 5383.4618044526. The cubic root of 28981661 is about 307.1669065925.

The spelling of 28981661 in words is "twenty-eight million, nine hundred eighty-one thousand, six hundred sixty-one".