28012382161 has 9 divisors (see below), whose sum is σ = 28950518793. Its totient is φ = 27103735860.

The previous prime is 28012382143. The next prime is 28012382197. The reversal of 28012382161 is 16128321082.

It is a happy number.

The square root of 28012382161 is 167369.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 28012382161 - 2⁵ = 28012382129 is a prime.

It is a super-2 number, since 2×28012382161² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28012382141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5185740 + ... + 5191138.

Almost surely, 2^28012382161 is an apocalyptic number.

28012382161 is the 167369-th square number.

28012382161 is the 83685-th centered octagonal number.

It is an amenable number.

28012382161 is a deficient number, since it is larger than the sum of its proper divisors (938136632).

28012382161 is an frugal number, since it uses more digits than its factorization.

28012382161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10860 (or 5430 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 34.

Multiplying 28012382161 by its product of nonzero digits (9216), we get a square (258162113995776 = 16067424²).

The spelling of 28012382161 in words is "twenty-eight billion, twelve million, three hundred eighty-two thousand, one hundred sixty-one".