28162661 has 4 divisors (see below), whose sum is σ = 28923852. Its totient is φ = 27401472.

The previous prime is 28162637. The next prime is 28162681. The reversal of 28162661 is 16626182.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25502500 + 2660161 = 5050^2 + 1631^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28162661 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28162681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 380540 + ... + 380613.

It is an arithmetic number, because the mean of its divisors is an integer number (7230963).

Almost surely, 2^28162661 is an apocalyptic number.

It is an amenable number.

28162661 is a deficient number, since it is larger than the sum of its proper divisors (761191).

28162661 is an equidigital number, since it uses as much as digits as its factorization.

28162661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761190.

The product of its digits is 6912, while the sum is 32.

The square root of 28162661 is about 5306.8503841733. The cubic root of 28162661 is about 304.2457795671.

The spelling of 28162661 in words is "twenty-eight million, one hundred sixty-two thousand, six hundred sixty-one".