61051105991 has 2 divisors, whose sum is σ = 61051105992. Its totient is φ = 61051105990.

The previous prime is 61051105961. The next prime is 61051106063. The reversal of 61051105991 is 19950115016.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61051105991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61051105961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30525552995 + 30525552996.

It is an arithmetic number, because the mean of its divisors is an integer number (30525552996).

Almost surely, 2^61051105991 is an apocalyptic number.

61051105991 is a deficient number, since it is larger than the sum of its proper divisors (1).

61051105991 is an equidigital number, since it uses as much as digits as its factorization.

61051105991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12150, while the sum is 38.

The spelling of 61051105991 in words is "sixty-one billion, fifty-one million, one hundred five thousand, nine hundred ninety-one".