28011400 has 24 divisors (see below), whose sum is σ = 65126970. Its totient is φ = 11204480.

The previous prime is 28011397. The next prime is 28011433. The reversal of 28011400 is 411082.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 13586596 + 14424804 = 3686^2 + 3798^2 .

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 5 ways as a sum of consecutive naturals, for example, 69829 + ... + 70228.

Almost surely, 2^28011400 is an apocalyptic number.

28011400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28011400 is an abundant number, since it is smaller than the sum of its proper divisors (37115570).

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

28011400 is a wasteful number, since it uses less digits than its factorization.

28011400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140073 (or 140064 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 28011400 is about 5292.5797112561. The cubic root of 28011400 is about 303.7001024463.

Adding to 28011400 its reverse (411082), we get a palindrome (28422482).

It can be divided in two parts, 2801 and 1400, that multiplied together give a triangular number (3921400 = T₂₈₀₀).

The spelling of 28011400 in words is "twenty-eight million, eleven thousand, four hundred".