28006420 has 24 divisors (see below), whose sum is σ = 63338184. Its totient is φ = 10340736.

The previous prime is 28006417. The next prime is 28006439. The reversal of 28006420 is 2460082.

It can be written as a sum of positive squares in 4 ways, for example, as 1156 + 28005264 = 34^2 + 5292^2 .

It is a super-2 number, since 2×28006420² = 1568719122432800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28006391 and 28006400.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53599 + ... + 54118.

It is an arithmetic number, because the mean of its divisors is an integer number (2639091).

Almost surely, 2^28006420 is an apocalyptic number.

28006420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28006420 is an abundant number, since it is smaller than the sum of its proper divisors (35331764).

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

28006420 is a wasteful number, since it uses less digits than its factorization.

28006420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107739 (or 107737 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 28006420 is about 5292.1092203393. The cubic root of 28006420 is about 303.6821036297.

The spelling of 28006420 in words is "twenty-eight million, six thousand, four hundred twenty".