28820385 has 72 divisors (see below), whose sum is σ = 56434560. Its totient is φ = 13590720.

The previous prime is 28820383. The next prime is 28820387. The reversal of 28820385 is 58302882.

It is an interprime number because it is at equal distance from previous prime (28820383) and next prime (28820387).

It is not a de Polignac number, because 28820385 - 2¹ = 28820383 is a prime.

It is a super-2 number, since 2×28820385² = 1661229183096450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28820381) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 364776 + ... + 364854.

Almost surely, 2^28820385 is an apocalyptic number.

It is an amenable number.

28820385 is a deficient number, since it is larger than the sum of its proper divisors (27614175).

28820385 is a wasteful number, since it uses less digits than its factorization.

28820385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 165 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The square root of 28820385 is about 5368.4620702767. The cubic root of 28820385 is about 306.5960763537.

The spelling of 28820385 in words is "twenty-eight million, eight hundred twenty thousand, three hundred eighty-five".