28981000 has 64 divisors (see below), whose sum is σ = 68917680. Its totient is φ = 11404800.

The previous prime is 28980949. The next prime is 28981021. The reversal of 28981000 is 18982.

It can be written as a sum of positive squares in 8 ways, for example, as 2540836 + 26440164 = 1594^2 + 5142^2 .

It is a super-2 number, since 2×28981000² = 1679796722000000, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28981000.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72802 + ... + 73198.

Almost surely, 2^28981000 is an apocalyptic number.

28981000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28981000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34458840).

28981000 is an abundant number, since it is smaller than the sum of its proper divisors (39936680).

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

28981000 is a wasteful number, since it uses less digits than its factorization.

28981000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 491 (or 477 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 28981000 is about 5383.4004123788. The cubic root of 28981000 is about 307.1645713356.

Adding to 28981000 its reverse (18982), we get a palindrome (28999982).

The spelling of 28981000 in words is "twenty-eight million, nine hundred eighty-one thousand".