28553391 has 10 divisors (see below), whose sum is σ = 42653952. Its totient is φ = 19035540.

The previous prime is 28553383. The next prime is 28553443. The reversal of 28553391 is 19335582.

It is not a de Polignac number, because 28553391 - 2³ = 28553383 is a prime.

It is a super-2 number, since 2×28553391² = 1630592275197762, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28553311) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 176175 + ... + 176336.

Almost surely, 2^28553391 is an apocalyptic number.

28553391 is a deficient number, since it is larger than the sum of its proper divisors (14100561).

28553391 is an equidigital number, since it uses as much as digits as its factorization.

28553391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352523 (or 352514 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 28553391 is about 5343.5373115568. The cubic root of 28553391 is about 305.6463619379.

The spelling of 28553391 in words is "twenty-eight million, five hundred fifty-three thousand, three hundred ninety-one".