28027581 has 8 divisors (see below), whose sum is σ = 37655904. Its totient is φ = 18542160.

The previous prime is 28027579. The next prime is 28027583. The reversal of 28027581 is 18572082.

28027581 = 396² + 397² + ... + 526².

It is an interprime number because it is at equal distance from previous prime (28027579) and next prime (28027583).

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

It is not a de Polignac number, because 28027581 - 2¹ = 28027579 is a prime.

It is a super-2 number, since 2×28027581² = 1571090593423122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28027583) 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, 35266 + ... + 36051.

It is an arithmetic number, because the mean of its divisors is an integer number (4706988).

Almost surely, 2^28027581 is an apocalyptic number.

It is an amenable number.

28027581 is a deficient number, since it is larger than the sum of its proper divisors (9628323).

28027581 is a wasteful number, since it uses less digits than its factorization.

28027581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71451.

The product of its (nonzero) digits is 8960, while the sum is 33.

The square root of 28027581 is about 5294.1081401875. The cubic root of 28027581 is about 303.7585694207.

The spelling of 28027581 in words is "twenty-eight million, twenty-seven thousand, five hundred eighty-one".