28520105 has 8 divisors (see below), whose sum is σ = 34253064. Its totient is φ = 22796800.

The previous prime is 28520099. The next prime is 28520111. The reversal of 28520105 is 50102582.

It is an interprime number because it is at equal distance from previous prime (28520099) and next prime (28520111).

It can be written as a sum of positive squares in 4 ways, for example, as 683929 + 27836176 = 827^2 + 5276^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28520105 - 2¹⁴ = 28503721 is a prime.

It is a super-2 number, since 2×28520105² = 1626792778422050, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9035 + ... + 11775.

It is an arithmetic number, because the mean of its divisors is an integer number (4281633).

Almost surely, 2^28520105 is an apocalyptic number.

It is an amenable number.

28520105 is a deficient number, since it is larger than the sum of its proper divisors (5732959).

28520105 is a wasteful number, since it uses less digits than its factorization.

28520105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4827.

The product of its (nonzero) digits is 800, while the sum is 23.

The square root of 28520105 is about 5340.4217998207. The cubic root of 28520105 is about 305.5275470868.

Adding to 28520105 its sum of digits (23), we get a triangular number (28520128 = T₇₅₅₂).

Adding to 28520105 its reverse (50102582), we get a palindrome (78622687).

The spelling of 28520105 in words is "twenty-eight million, five hundred twenty thousand, one hundred five".