61550561 has 4 divisors (see below), whose sum is σ = 61642692. Its totient is φ = 61458432.

The previous prime is 61550549. The next prime is 61550563. The reversal of 61550561 is 16505516.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15649936 + 45900625 = 3956^2 + 6775^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61550561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61550563) 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, 45056 + ... + 46401.

It is an arithmetic number, because the mean of its divisors is an integer number (15410673).

Almost surely, 2^61550561 is an apocalyptic number.

It is an amenable number.

61550561 is a deficient number, since it is larger than the sum of its proper divisors (92131).

61550561 is an equidigital number, since it uses as much as digits as its factorization.

61550561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92130.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 61550561 is about 7845.4165600050. The cubic root of 61550561 is about 394.8304800545.

The spelling of 61550561 in words is "sixty-one million, five hundred fifty thousand, five hundred sixty-one".