1999136006721 has 64 divisors (see below), whose sum is σ = 3427266752000. Its totient is φ = 1142130481920.

The previous prime is 1999136006719. The next prime is 1999136006761. The reversal of 1999136006721 is 1276006319991.

1999136006721 is a `hidden beast` number, since 1 + 9 + 9 + 9 + 1 + 3 + 600 + 6 + 7 + 21 = 666.

It is not a de Polignac number, because 1999136006721 - 2¹ = 1999136006719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1999136006761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 99207555 + ... + 99227703.

It is an arithmetic number, because the mean of its divisors is an integer number (53551043000).

Almost surely, 2^{1999136006721} is an apocalyptic number.

It is an amenable number.

1999136006721 is a deficient number, since it is larger than the sum of its proper divisors (1428130745279).

1999136006721 is an frugal number, since it uses more digits than its factorization.

1999136006721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26658 (or 26640 counting only the distinct ones).

The product of its (nonzero) digits is 1102248, while the sum is 54.

The spelling of 1999136006721 in words is "one trillion, nine hundred ninety-nine billion, one hundred thirty-six million, six thousand, seven hundred twenty-one".