28201669 has 4 divisors (see below), whose sum is σ = 28465344. Its totient is φ = 27937996.

The previous prime is 28201639. The next prime is 28201673. The reversal of 28201669 is 96610282.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28201669 - 2⁵ = 28201637 is a prime.

It is a super-2 number, since 2×28201669² = 1590668268771122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28201609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131677 + ... + 131890.

It is an arithmetic number, because the mean of its divisors is an integer number (7116336).

Almost surely, 2^28201669 is an apocalyptic number.

It is an amenable number.

28201669 is a deficient number, since it is larger than the sum of its proper divisors (263675).

28201669 is a wasteful number, since it uses less digits than its factorization.

28201669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263674.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 28201669 is about 5310.5243620569. The cubic root of 28201669 is about 304.3861846722.

It can be divided in two parts, 2820 and 1669, that added together give a square (4489 = 67²).

The spelling of 28201669 in words is "twenty-eight million, two hundred one thousand, six hundred sixty-nine".