99721884181643 has 2 divisors, whose sum is σ = 99721884181644. Its totient is φ = 99721884181642.

The previous prime is 99721884181609. The next prime is 99721884181651. The reversal of 99721884181643 is 34618148812799.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 99721884181643 - 2³⁴ = 99704704312459 is a prime.

It is not a weakly prime, because it can be changed into another prime (99721884481643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49860942090821 + 49860942090822.

It is an arithmetic number, because the mean of its divisors is an integer number (49860942090822).

Almost surely, 2^{99721884181643} is an apocalyptic number.

99721884181643 is a deficient number, since it is larger than the sum of its proper divisors (1).

99721884181643 is an equidigital number, since it uses as much as digits as its factorization.

99721884181643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 167215104, while the sum is 71.

The spelling of 99721884181643 in words is "ninety-nine trillion, seven hundred twenty-one billion, eight hundred eighty-four million, one hundred eighty-one thousand, six hundred forty-three".