28601320981 has 2 divisors, whose sum is σ = 28601320982. Its totient is φ = 28601320980.

The previous prime is 28601320949. The next prime is 28601321003. The reversal of 28601320981 is 18902310682.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25859856100 + 2741464881 = 160810^2 + 52359^2 .

It is a cyclic number.

It is not a de Polignac number, because 28601320981 - 2⁵ = 28601320949 is a prime.

It is a super-2 number, since 2×28601320981² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28601320481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14300660490 + 14300660491.

It is an arithmetic number, because the mean of its divisors is an integer number (14300660491).

Almost surely, 2^28601320981 is an apocalyptic number.

It is an amenable number.

28601320981 is a deficient number, since it is larger than the sum of its proper divisors (1).

28601320981 is an equidigital number, since it uses as much as digits as its factorization.

28601320981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 40.

The spelling of 28601320981 in words is "twenty-eight billion, six hundred one million, three hundred twenty thousand, nine hundred eighty-one".