28081556 has 24 divisors (see below), whose sum is σ = 50972544. Its totient is φ = 13526720.

The previous prime is 28081523. The next prime is 28081589. The reversal of 28081556 is 65518082.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28081523) and next prime (28081589).

It is a super-2 number, since 2×28081556² = 1577147574762272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12581 + ... + 14643.

It is an arithmetic number, because the mean of its divisors is an integer number (2123856).

Almost surely, 2^28081556 is an apocalyptic number.

It is an amenable number.

28081556 is a deficient number, since it is larger than the sum of its proper divisors (22890988).

28081556 is a wasteful number, since it uses less digits than its factorization.

28081556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2191 (or 2189 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 35.

The square root of 28081556 is about 5299.2033363516. The cubic root of 28081556 is about 303.9534352732.

The spelling of 28081556 in words is "twenty-eight million, eighty-one thousand, five hundred fifty-six".