28131012 has 144 divisors (see below), whose sum is σ = 90668032. Its totient is φ = 7153920.

The previous prime is 28130953. The next prime is 28131013. The reversal of 28131012 is 21013182.

It is a super-2 number, since 2×28131012² = 1582707672288288, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (28131013) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 101418 + ... + 101694.

Almost surely, 2^28131012 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28131012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45334016).

28131012 is an abundant number, since it is smaller than the sum of its proper divisors (62537020).

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

28131012 is a wasteful number, since it uses less digits than its factorization.

28131012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338 (or 333 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 28131012 is about 5303.8676454075. The cubic root of 28131012 is about 304.1317670932.

Adding to 28131012 its reverse (21013182), we get a palindrome (49144194).

The spelling of 28131012 in words is "twenty-eight million, one hundred thirty-one thousand, twelve".