28169391 has 8 divisors (see below), whose sum is σ = 39768624. Its totient is φ = 17674880.

The previous prime is 28169389. The next prime is 28169423. The reversal of 28169391 is 19396182.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28169391 - 2¹ = 28169389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28169891) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 276120 + ... + 276221.

It is an arithmetic number, because the mean of its divisors is an integer number (4971078).

Almost surely, 2^28169391 is an apocalyptic number.

28169391 is a deficient number, since it is larger than the sum of its proper divisors (11599233).

28169391 is a wasteful number, since it uses less digits than its factorization.

28169391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 552361.

The product of its digits is 23328, while the sum is 39.

The square root of 28169391 is about 5307.4844323841. The cubic root of 28169391 is about 304.2700127296.

The spelling of 28169391 in words is "twenty-eight million, one hundred sixty-nine thousand, three hundred ninety-one".