999507514981 has 2 divisors, whose sum is σ = 999507514982. Its totient is φ = 999507514980.

The previous prime is 999507514979. The next prime is 999507514987. The reversal of 999507514981 is 189415705999.

999507514981 = T₈₁₆₂₉₄ + T₈₁₆₂₉₅ + T₈₁₆₂₉₆.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 653017529025 + 346489985956 = 808095^2 + 588634^2 .

It is a cyclic number.

It is not a de Polignac number, because 999507514981 - 2¹ = 999507514979 is a prime.

It is a super-2 number, since 2×999507514981² (a number of 25 digits) contains 22 as substring.

Together with 999507514979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999507514987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499753757490 + 499753757491.

It is an arithmetic number, because the mean of its divisors is an integer number (499753757491).

Almost surely, 2^999507514981 is an apocalyptic number.

999507514981 is the 816296-th centered triangular number.

It is an amenable number.

999507514981 is a deficient number, since it is larger than the sum of its proper divisors (1).

999507514981 is an equidigital number, since it uses as much as digits as its factorization.

999507514981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36741600, while the sum is 67.

The spelling of 999507514981 in words is "nine hundred ninety-nine billion, five hundred seven million, five hundred fourteen thousand, nine hundred eighty-one".