64525561 has 4 divisors (see below), whose sum is σ = 64541824. Its totient is φ = 64509300.

The previous prime is 64525529. The next prime is 64525579. The reversal of 64525561 is 16552546.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16552546 = 2 ⋅8276273.

It is a cyclic number.

It is not a de Polignac number, because 64525561 - 2⁵ = 64525529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64525361) 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, 2176 + ... + 11566.

It is an arithmetic number, because the mean of its divisors is an integer number (16135456).

Almost surely, 2^64525561 is an apocalyptic number.

It is an amenable number.

64525561 is a deficient number, since it is larger than the sum of its proper divisors (16263).

64525561 is an equidigital number, since it uses as much as digits as its factorization.

64525561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16262.

The product of its digits is 36000, while the sum is 34.

The square root of 64525561 is about 8032.7804028244. The cubic root of 64525561 is about 401.0919352313.

It can be divided in two parts, 64 and 525561, that added together give a square (525625 = 725²).

The spelling of 64525561 in words is "sixty-four million, five hundred twenty-five thousand, five hundred sixty-one".