1995821880 has 128 divisors (see below), whose sum is σ = 6461017920. Its totient is φ = 490291200.

The previous prime is 1995821797. The next prime is 1995821953. The reversal of 1995821880 is 881285991.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 1048930 + ... + 1050830.

Almost surely, 2^1995821880 is an apocalyptic number.

1995821880 is a gapful number since it is divisible by the number (10) 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 1995821880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3230508960).

1995821880 is an abundant number, since it is smaller than the sum of its proper divisors (4465196040).

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

1995821880 is a wasteful number, since it uses less digits than its factorization.

1995821880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2601 (or 2597 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 51.

The square root of 1995821880 is about 44674.6223263275. The cubic root of 1995821880 is about 1259.0430880162.

The spelling of 1995821880 in words is "one billion, nine hundred ninety-five million, eight hundred twenty-one thousand, eight hundred eighty".