1999911000990 has 256 divisors, whose sum is σ = 5789501982720. Its totient is φ = 432447375360.

The previous prime is 1999911000959. The next prime is 1999911001051. The reversal of 1999911000990 is 990001199991.

1999911000990 is a nontrivial binomial coefficient, being equal to C(1999956, 2).

It is a self number, because there is not a number n which added to its sum of digits gives 1999911000990.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 264990397 + ... + 264997943.

It is an arithmetic number, because the mean of its divisors is an integer number (22615242120).

Almost surely, 2^{1999911000990} is an apocalyptic number.

1999911000990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1999911000990 is the 1999955-th triangular number and also the 999978-th hexagonal number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1999911000990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2894750991360).

1999911000990 is an abundant number, since it is smaller than the sum of its proper divisors (3789590981730).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1999911000990 is a wasteful number, since it uses less digits than its factorization.

1999911000990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8467.

The product of its (nonzero) digits is 531441, while the sum is 57.

The spelling of 1999911000990 in words is "one trillion, nine hundred ninety-nine billion, nine hundred eleven million, nine hundred ninety", and thus it is an aban number.