61544561 has 16 divisors (see below), whose sum is σ = 67544400. Its totient is φ = 56070144.

The previous prime is 61544557. The next prime is 61544563. The reversal of 61544561 is 16544516.

61544561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 16654561 + 44890000 = 4081^2 + 6700^2 .

It is not a de Polignac number, because 61544561 - 2² = 61544557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61544563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 239345 + ... + 239601.

It is an arithmetic number, because the mean of its divisors is an integer number (4221525).

Almost surely, 2^61544561 is an apocalyptic number.

It is an amenable number.

61544561 is a deficient number, since it is larger than the sum of its proper divisors (5999839).

61544561 is a wasteful number, since it uses less digits than its factorization.

61544561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405 (or 379 counting only the distinct ones).

The product of its digits is 14400, while the sum is 32.

The square root of 61544561 is about 7845.0341618122. The cubic root of 61544561 is about 394.8176501695.

The spelling of 61544561 in words is "sixty-one million, five hundred forty-four thousand, five hundred sixty-one".