28161481 has 2 divisors, whose sum is σ = 28161482. Its totient is φ = 28161480.

The previous prime is 28161473. The next prime is 28161487. The reversal of 28161481 is 18416182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27040000 + 1121481 = 5200^2 + 1059^2 .

It is a cyclic number.

It is not a de Polignac number, because 28161481 - 2³ = 28161473 is a prime.

It is a super-2 number, since 2×28161481² = 1586138024226722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (28161487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14080740 + 14080741.

It is an arithmetic number, because the mean of its divisors is an integer number (14080741).

Almost surely, 2^28161481 is an apocalyptic number.

It is an amenable number.

28161481 is a deficient number, since it is larger than the sum of its proper divisors (1).

28161481 is an equidigital number, since it uses as much as digits as its factorization.

28161481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3072, while the sum is 31.

The square root of 28161481 is about 5306.7392059531. The cubic root of 28161481 is about 304.2415302642.

The spelling of 28161481 in words is "twenty-eight million, one hundred sixty-one thousand, four hundred eighty-one".