1991339160 has 128 divisors (see below), whose sum is σ = 6094932480. Its totient is φ = 520363008.

The previous prime is 1991339153. The next prime is 1991339171. The reversal of 1991339160 is 619331991.

It is a congruent number.

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, 1872789 + ... + 1873851.

It is an arithmetic number, because the mean of its divisors is an integer number (47616660).

Almost surely, 2^1991339160 is an apocalyptic number.

1991339160 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 1991339160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3047466240).

1991339160 is an abundant number, since it is smaller than the sum of its proper divisors (4103593320).

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

1991339160 is a wasteful number, since it uses less digits than its factorization.

1991339160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1377 (or 1373 counting only the distinct ones).

The product of its (nonzero) digits is 39366, while the sum is 42.

The square root of 1991339160 is about 44624.4233576189. The cubic root of 1991339160 is about 1258.0997559326.

The spelling of 1991339160 in words is "one billion, nine hundred ninety-one million, three hundred thirty-nine thousand, one hundred sixty".