61656191 has 2 divisors, whose sum is σ = 61656192. Its totient is φ = 61656190.

The previous prime is 61656181. The next prime is 61656209. The reversal of 61656191 is 19165616.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61656191 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61656131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30828095 + 30828096.

It is an arithmetic number, because the mean of its divisors is an integer number (30828096).

Almost surely, 2^61656191 is an apocalyptic number.

61656191 is a deficient number, since it is larger than the sum of its proper divisors (1).

61656191 is an equidigital number, since it uses as much as digits as its factorization.

61656191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9720, while the sum is 35.

The square root of 61656191 is about 7852.1456303357. The cubic root of 61656191 is about 395.0562137590.

The spelling of 61656191 in words is "sixty-one million, six hundred fifty-six thousand, one hundred ninety-one".