999977648129 has 2 divisors, whose sum is σ = 999977648130. Its totient is φ = 999977648128.

The previous prime is 999977648119. The next prime is 999977648207. The reversal of 999977648129 is 921846779999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 626353530625 + 373624117504 = 791425^2 + 611248^2 .

It is a cyclic number.

It is not a de Polignac number, because 999977648129 - 2⁴ = 999977648113 is a prime.

It is a super-2 number, since 2×999977648129² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (999977648119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499988824064 + 499988824065.

It is an arithmetic number, because the mean of its divisors is an integer number (499988824065).

It is a Proth number, since it is equal to 953653 ⋅ 2²⁰ + 1 and 953653 < 2²⁰.

Almost surely, 2^999977648129 is an apocalyptic number.

It is an amenable number.

999977648129 is a deficient number, since it is larger than the sum of its proper divisors (1).

999977648129 is an equidigital number, since it uses as much as digits as its factorization.

999977648129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1111065984, while the sum is 80.

The spelling of 999977648129 in words is "nine hundred ninety-nine billion, nine hundred seventy-seven million, six hundred forty-eight thousand, one hundred twenty-nine".