1991195136 has 400 divisors, whose sum is σ = 7169511360. Its totient is φ = 538970112.

The previous prime is 1991195119. The next prime is 1991195161. The reversal of 1991195136 is 6315911991.

1991195136 is a `hidden beast` number, since 19 + 9 + 119 + 513 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 1991195091 and 1991195100.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 104799735 + ... + 104799753.

Almost surely, 2^1991195136 is an apocalyptic number.

1991195136 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 1991195136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3584755680).

1991195136 is an abundant number, since it is smaller than the sum of its proper divisors (5178316224).

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

1991195136 is an frugal number, since it uses more digits than its factorization.

1991195136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94 (or 31 counting only the distinct ones).

The product of its digits is 65610, while the sum is 45.

The square root of 1991195136 is about 44622.8095933010. The cubic root of 1991195136 is about 1258.0694244298.

The spelling of 1991195136 in words is "one billion, nine hundred ninety-one million, one hundred ninety-five thousand, one hundred thirty-six".