28525561 has 4 divisors (see below), whose sum is σ = 28714624. Its totient is φ = 28336500.

The previous prime is 28525559. The next prime is 28525579. The reversal of 28525561 is 16552582.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28525561 - 2¹ = 28525559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28525361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94305 + ... + 94606.

It is an arithmetic number, because the mean of its divisors is an integer number (7178656).

Almost surely, 2^28525561 is an apocalyptic number.

It is an amenable number.

28525561 is a deficient number, since it is larger than the sum of its proper divisors (189063).

28525561 is a wasteful number, since it uses less digits than its factorization.

28525561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189062.

The product of its digits is 24000, while the sum is 34.

The square root of 28525561 is about 5340.9325964667. The cubic root of 28525561 is about 305.5470286889.

The spelling of 28525561 in words is "twenty-eight million, five hundred twenty-five thousand, five hundred sixty-one".