61223561 has 4 divisors (see below), whose sum is σ = 69969792. Its totient is φ = 52477332.

The previous prime is 61223557. The next prime is 61223597. The reversal of 61223561 is 16532216.

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 61223561 - 2² = 61223557 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61223561.

It is not an unprimeable number, because it can be changed into a prime (61223521) 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, 4373105 + ... + 4373118.

It is an arithmetic number, because the mean of its divisors is an integer number (17492448).

Almost surely, 2^61223561 is an apocalyptic number.

It is an amenable number.

61223561 is a deficient number, since it is larger than the sum of its proper divisors (8746231).

61223561 is an equidigital number, since it uses as much as digits as its factorization.

61223561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8746230.

The product of its digits is 2160, while the sum is 26.

The square root of 61223561 is about 7824.5486131789. The cubic root of 61223561 is about 394.1300321492.

Adding to 61223561 its reverse (16532216), we get a palindrome (77755777).

The spelling of 61223561 in words is "sixty-one million, two hundred twenty-three thousand, five hundred sixty-one".