28181532 has 24 divisors (see below), whose sum is σ = 68616576. Its totient is φ = 8985328.

The previous prime is 28181513. The next prime is 28181539. The reversal of 28181532 is 23518182.

It is a self number, because there is not a number n which added to its sum of digits gives 28181532.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28181539) 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, 50778 + ... + 51329.

It is an arithmetic number, because the mean of its divisors is an integer number (2859024).

Almost surely, 2^28181532 is an apocalyptic number.

It is an amenable number.

28181532 is an abundant number, since it is smaller than the sum of its proper divisors (40435044).

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

28181532 is a wasteful number, since it uses less digits than its factorization.

28181532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102137 (or 102135 counting only the distinct ones).

The product of its digits is 3840, while the sum is 30.

The square root of 28181532 is about 5308.6280713570. The cubic root of 28181532 is about 304.3137198823.

The spelling of 28181532 in words is "twenty-eight million, one hundred eighty-one thousand, five hundred thirty-two".