1991436050 has 18 divisors (see below), whose sum is σ = 3704658069. Its totient is φ = 796448200.

The previous prime is 1991436023. The next prime is 1991436059. The reversal of 1991436050 is 506341991.

It can be written as a sum of positive squares in 2 ways, for example, as 1951607329 + 39828721 = 44177^2 + 6311^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=31555.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1991435995 and 1991436013.

It is not an unprimeable number, because it can be changed into a prime (1991436059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 312395 + ... + 318705.

Almost surely, 2^1991436050 is an apocalyptic number.

1991436050 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1991436050 is a deficient number, since it is larger than the sum of its proper divisors (1713222019).

1991436050 is an frugal number, since it uses more digits than its factorization.

1991436050 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12634 (or 6318 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 38.

The square root of 1991436050 is about 44625.5089606830. The cubic root of 1991436050 is about 1258.1201601762.

The spelling of 1991436050 in words is "one billion, nine hundred ninety-one million, four hundred thirty-six thousand, fifty".