99943867420961 has 2 divisors, whose sum is σ = 99943867420962. Its totient is φ = 99943867420960.

The previous prime is 99943867420883. The next prime is 99943867420973. The reversal of 99943867420961 is 16902476834999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59075272369936 + 40868595051025 = 7686044^2 + 6392855^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99943867420961 is a prime.

It is not a weakly prime, because it can be changed into another prime (99943867120961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49971933710480 + 49971933710481.

It is an arithmetic number, because the mean of its divisors is an integer number (49971933710481).

Almost surely, 2^{99943867420961} is an apocalyptic number.

It is an amenable number.

99943867420961 is a deficient number, since it is larger than the sum of its proper divisors (1).

99943867420961 is an equidigital number, since it uses as much as digits as its factorization.

99943867420961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1269789696, while the sum is 77.

The spelling of 99943867420961 in words is "ninety-nine trillion, nine hundred forty-three billion, eight hundred sixty-seven million, four hundred twenty thousand, nine hundred sixty-one".