28635561 has 12 divisors (see below), whose sum is σ = 41497092. Its totient is φ = 19028256.

The previous prime is 28635553. The next prime is 28635569. The reversal of 28635561 is 16553682.

It is an interprime number because it is at equal distance from previous prime (28635553) and next prime (28635569).

It can be written as a sum of positive squares in 2 ways, for example, as 4928400 + 23707161 = 2220^2 + 4869^2 .

It is not a de Polignac number, because 28635561 - 2³ = 28635553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28635569) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2166 + ... + 7871.

It is an arithmetic number, because the mean of its divisors is an integer number (3458091).

Almost surely, 2^28635561 is an apocalyptic number.

It is an amenable number.

28635561 is a deficient number, since it is larger than the sum of its proper divisors (12861531).

28635561 is a wasteful number, since it uses less digits than its factorization.

28635561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10360 (or 10357 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 28635561 is about 5351.2205149853. The cubic root of 28635561 is about 305.9392741217.

The spelling of 28635561 in words is "twenty-eight million, six hundred thirty-five thousand, five hundred sixty-one".