28481985 has 36 divisors (see below), whose sum is σ = 57433428. Its totient is φ = 13019328.

The previous prime is 28481977. The next prime is 28481993. The reversal of 28481985 is 58918482.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28481977) and next prime (28481993).

It can be written as a sum of positive squares in 2 ways, for example, as 12895281 + 15586704 = 3591^2 + 3948^2 .

It is not a de Polignac number, because 28481985 - 2³ = 28481977 is a prime.

It is a super-2 number, since 2×28481985² = 1622446939080450, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28481985.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 4254 + ... + 8663.

It is an arithmetic number, because the mean of its divisors is an integer number (1595373).

Almost surely, 2^28481985 is an apocalyptic number.

It is an amenable number.

28481985 is an abundant number, since it is smaller than the sum of its proper divisors (28951443).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28481985 is a wasteful number, since it uses less digits than its factorization.

28481985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12942 (or 12932 counting only the distinct ones).

The product of its digits is 184320, while the sum is 45.

The square root of 28481985 is about 5336.8515999604. The cubic root of 28481985 is about 305.3913635892.

The spelling of 28481985 in words is "twenty-eight million, four hundred eighty-one thousand, nine hundred eighty-five".