61000561 has 4 divisors (see below), whose sum is σ = 61772800. Its totient is φ = 60228324.

The previous prime is 61000553. The next prime is 61000571. The reversal of 61000561 is 16500016.

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 61000561 - 2³ = 61000553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61000571) 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, 386001 + ... + 386158.

It is an arithmetic number, because the mean of its divisors is an integer number (15443200).

Almost surely, 2^61000561 is an apocalyptic number.

It is an amenable number.

61000561 is a deficient number, since it is larger than the sum of its proper divisors (772239).

61000561 is an equidigital number, since it uses as much as digits as its factorization.

61000561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 772238.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 61000561 is about 7810.2855901689. The cubic root of 61000561 is about 393.6509250688.

Adding to 61000561 its reverse (16500016), we get a palindrome (77500577).

The spelling of 61000561 in words is "sixty-one million, five hundred sixty-one", and thus it is an aban number.