1991916576 has 192 divisors, whose sum is σ = 6317942400. Its totient is φ = 606901248.

The previous prime is 1991916559. The next prime is 1991916599. The reversal of 1991916576 is 6756191991.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1223475 + ... + 1225101.

It is an arithmetic number, because the mean of its divisors is an integer number (32905950).

Almost surely, 2^1991916576 is an apocalyptic number.

1991916576 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1991916576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3158971200).

1991916576 is an abundant number, since it is smaller than the sum of its proper divisors (4326025824).

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

1991916576 is a wasteful number, since it uses less digits than its factorization.

1991916576 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1768 (or 1754 counting only the distinct ones).

The product of its digits is 918540, while the sum is 54.

The square root of 1991916576 is about 44630.8926193506. The cubic root of 1991916576 is about 1258.2213452530.

The spelling of 1991916576 in words is "one billion, nine hundred ninety-one million, nine hundred sixteen thousand, five hundred seventy-six".