999987943501 has 2 divisors, whose sum is σ = 999987943502. Its totient is φ = 999987943500.

The previous prime is 999987943499. The next prime is 999987943609. The reversal of 999987943501 is 105349789999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 774197613225 + 225790330276 = 879885^2 + 475174^2 .

It is a cyclic number.

It is not a de Polignac number, because 999987943501 - 2¹ = 999987943499 is a prime.

Together with 999987943499, 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 (999987943901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499993971750 + 499993971751.

It is an arithmetic number, because the mean of its divisors is an integer number (499993971751).

Almost surely, 2^999987943501 is an apocalyptic number.

It is an amenable number.

999987943501 is a deficient number, since it is larger than the sum of its proper divisors (1).

999987943501 is an equidigital number, since it uses as much as digits as its factorization.

999987943501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 198404640, while the sum is 73.

The spelling of 999987943501 in words is "nine hundred ninety-nine billion, nine hundred eighty-seven million, nine hundred forty-three thousand, five hundred one".