1999997776 has 80 divisors (see below), whose sum is σ = 4733375616. Its totient is φ = 799100928.

The previous prime is 1999997773. The next prime is 1999997777. The reversal of 1999997776 is 6777999991.

It is a super-2 number, since 2×1999997776² = 7999982208009892352, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1999997699 and 1999997708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999997773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 198820 + ... + 208636.

Almost surely, 2^1999997776 is an apocalyptic number.

1999997776 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 1999997776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2366687808).

1999997776 is an abundant number, since it is smaller than the sum of its proper divisors (2733377840).

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

1999997776 is a wasteful number, since it uses less digits than its factorization.

1999997776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9956 (or 9950 counting only the distinct ones).

The product of its digits is 121522842, while the sum is 73.

The square root of 1999997776 is about 44721.3346849130. The cubic root of 1999997776 is about 1259.9205828840.

The spelling of 1999997776 in words is "one billion, nine hundred ninety-nine million, nine hundred ninety-seven thousand, seven hundred seventy-six".