999943045121 has 2 divisors, whose sum is σ = 999943045122. Its totient is φ = 999943045120.

The previous prime is 999943045097. The next prime is 999943045147. The reversal of 999943045121 is 121540349999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 749306640625 + 250636404496 = 865625^2 + 500636^2 .

It is an emirp because it is prime and its reverse (121540349999) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-999943045121 is a prime.

It is not a weakly prime, because it can be changed into another prime (999943045181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499971522560 + 499971522561.

It is an arithmetic number, because the mean of its divisors is an integer number (499971522561).

It is a Proth number, since it is equal to 238405 ⋅ 2²² + 1 and 238405 < 2²².

Almost surely, 2^999943045121 is an apocalyptic number.

It is an amenable number.

999943045121 is a deficient number, since it is larger than the sum of its proper divisors (1).

999943045121 is an equidigital number, since it uses as much as digits as its factorization.

999943045121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3149280, while the sum is 56.

The spelling of 999943045121 in words is "nine hundred ninety-nine billion, nine hundred forty-three million, forty-five thousand, one hundred twenty-one".