28257331 has 8 divisors (see below), whose sum is σ = 28605584. Its totient is φ = 27911520.

The previous prime is 28257319. The next prime is 28257343. The reversal of 28257331 is 13375282.

It is an interprime number because it is at equal distance from previous prime (28257319) and next prime (28257343).

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 28257331 - 2¹³ = 28249139 is a prime.

It is a super-2 number, since 2×28257331² = 1596953510487122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28257293 and 28257302.

It is not an unprimeable number, because it can be changed into a prime (28257311) 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, 32701 + ... + 33553.

It is an arithmetic number, because the mean of its divisors is an integer number (3575698).

Almost surely, 2^28257331 is an apocalyptic number.

28257331 is a deficient number, since it is larger than the sum of its proper divisors (348253).

28257331 is a wasteful number, since it uses less digits than its factorization.

28257331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1221.

The product of its digits is 10080, while the sum is 31.

The square root of 28257331 is about 5315.7625041004. The cubic root of 28257331 is about 304.5863100538.

The spelling of 28257331 in words is "twenty-eight million, two hundred fifty-seven thousand, three hundred thirty-one".