1991650506480 has 120 divisors (see below), whose sum is σ = 6690217379040. Its totient is φ = 530980462080.

The previous prime is 1991650506437. The next prime is 1991650506497. The reversal of 1991650506480 is 846050561991.

1991650506480 is a `hidden beast` number, since 1 + 9 + 9 + 1 + 6 + 50 + 506 + 4 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2719426 + ... + 3373214.

It is an arithmetic number, because the mean of its divisors is an integer number (55751811492).

Almost surely, 2^{1991650506480} is an apocalyptic number.

1991650506480 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1991650506480 is an abundant number, since it is smaller than the sum of its proper divisors (4698566872560).

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

1991650506480 is a wasteful number, since it uses less digits than its factorization.

1991650506480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658039 (or 658030 counting only the distinct ones).

The product of its (nonzero) digits is 2332800, while the sum is 54.

The spelling of 1991650506480 in words is "one trillion, nine hundred ninety-one billion, six hundred fifty million, five hundred six thousand, four hundred eighty".