61561243 has 2 divisors, whose sum is σ = 61561244. Its totient is φ = 61561242.

The previous prime is 61561237. The next prime is 61561259. The reversal of 61561243 is 34216516.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61561243 is a prime.

It is not a weakly prime, because it can be changed into another prime (61561343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30780621 + 30780622.

It is an arithmetic number, because the mean of its divisors is an integer number (30780622).

Almost surely, 2^61561243 is an apocalyptic number.

61561243 is a deficient number, since it is larger than the sum of its proper divisors (1).

61561243 is an equidigital number, since it uses as much as digits as its factorization.

61561243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 28.

The square root of 61561243 is about 7846.0973101281. The cubic root of 61561243 is about 394.8533194631.

Adding to 61561243 its reverse (34216516), we get a palindrome (95777759).

The spelling of 61561243 in words is "sixty-one million, five hundred sixty-one thousand, two hundred forty-three".