28251591 has 8 divisors (see below), whose sum is σ = 37956864. Its totient is φ = 18690360.

The previous prime is 28251589. The next prime is 28251593. The reversal of 28251591 is 19515282.

It is an interprime number because it is at equal distance from previous prime (28251589) and next prime (28251593).

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

It is not a de Polignac number, because 28251591 - 2¹ = 28251589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28251593) 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, 35551 + ... + 36336.

It is an arithmetic number, because the mean of its divisors is an integer number (4744608).

Almost surely, 2^28251591 is an apocalyptic number.

28251591 is a deficient number, since it is larger than the sum of its proper divisors (9705273).

28251591 is a wasteful number, since it uses less digits than its factorization.

28251591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72021.

The product of its digits is 7200, while the sum is 33.

The square root of 28251591 is about 5315.2225729503. Note that the first 3 decimals coincide. The cubic root of 28251591 is about 304.5656848007.

The spelling of 28251591 in words is "twenty-eight million, two hundred fifty-one thousand, five hundred ninety-one".