28012700 has 72 divisors (see below), whose sum is σ = 63922992. Its totient is φ = 10644480.

The previous prime is 28012693. The next prime is 28012711. The reversal of 28012700 is 721082.

It is a super-2 number, since 2×28012700² = 1569422722580000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 247844 + ... + 247956.

Almost surely, 2^28012700 is an apocalyptic number.

28012700 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 28012700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31961496).

28012700 is an abundant number, since it is smaller than the sum of its proper divisors (35910292).

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

28012700 is a wasteful number, since it uses less digits than its factorization.

28012700 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231 (or 224 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 28012700 is about 5292.7025232862. The cubic root of 28012700 is about 303.7048005814.

Adding to 28012700 its reverse (721082), we get a palindrome (28733782).

The spelling of 28012700 in words is "twenty-eight million, twelve thousand, seven hundred".