28220535 has 32 divisors (see below), whose sum is σ = 57338880. Its totient is φ = 12900384.

The previous prime is 28220519. The next prime is 28220551. The reversal of 28220535 is 53502282.

It is an interprime number because it is at equal distance from previous prime (28220519) and next prime (28220551).

It is not a de Polignac number, because 28220535 - 2⁴ = 28220519 is a prime.

It is a super-3 number, since 3×28220535³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 28220499 and 28220508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13987 + ... + 15876.

It is an arithmetic number, because the mean of its divisors is an integer number (1791840).

Almost surely, 2^28220535 is an apocalyptic number.

28220535 is an abundant number, since it is smaller than the sum of its proper divisors (29118345).

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

28220535 is a wasteful number, since it uses less digits than its factorization.

28220535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29884 (or 29878 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 28220535 is about 5312.3003491896. The cubic root of 28220535 is about 304.4540443641.

The spelling of 28220535 in words is "twenty-eight million, two hundred twenty thousand, five hundred thirty-five".