28331247181 has 2 divisors, whose sum is σ = 28331247182. Its totient is φ = 28331247180.

The previous prime is 28331247179. The next prime is 28331247199. The reversal of 28331247181 is 18174213382.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17920105956 + 10411141225 = 133866^2 + 102035^2 .

It is a cyclic number.

It is not a de Polignac number, because 28331247181 - 2¹ = 28331247179 is a prime.

It is a super-2 number, since 2×28331247181² (a number of 22 digits) contains 22 as substring.

Together with 28331247179, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28331247151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14165623590 + 14165623591.

It is an arithmetic number, because the mean of its divisors is an integer number (14165623591).

Almost surely, 2^28331247181 is an apocalyptic number.

It is an amenable number.

28331247181 is a deficient number, since it is larger than the sum of its proper divisors (1).

28331247181 is an equidigital number, since it uses as much as digits as its factorization.

28331247181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 64512, while the sum is 40.

The spelling of 28331247181 in words is "twenty-eight billion, three hundred thirty-one million, two hundred forty-seven thousand, one hundred eighty-one".