61561121 has 8 divisors (see below), whose sum is σ = 65134080. Its totient is φ = 58021488.

The previous prime is 61561103. The next prime is 61561127. The reversal of 61561121 is 12116516.

61561121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61561121 - 2¹⁴ = 61544737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61561127) 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 7 ways as a sum of consecutive naturals, for example, 4481 + ... + 11966.

It is an arithmetic number, because the mean of its divisors is an integer number (8141760).

Almost surely, 2^61561121 is an apocalyptic number.

It is an amenable number.

61561121 is a deficient number, since it is larger than the sum of its proper divisors (3572959).

61561121 is a wasteful number, since it uses less digits than its factorization.

61561121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16663.

The product of its digits is 360, while the sum is 23.

The square root of 61561121 is about 7846.0895355585. The cubic root of 61561121 is about 394.8530586272.

Adding to 61561121 its reverse (12116516), we get a palindrome (73677637).

The spelling of 61561121 in words is "sixty-one million, five hundred sixty-one thousand, one hundred twenty-one".