1991436049 has 8 divisors (see below), whose sum is σ = 2110002048. Its totient is φ = 1873028160.

The previous prime is 1991436023. The next prime is 1991436059. The reversal of 1991436049 is 9406341991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1991436049 - 2¹³ = 1991427857 is a prime.

It is a Duffinian number.

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 7 ways as a sum of consecutive naturals, for example, 13077 + ... + 64450.

It is an arithmetic number, because the mean of its divisors is an integer number (263750256).

Almost surely, 2^1991436049 is an apocalyptic number.

It is an amenable number.

1991436049 is a deficient number, since it is larger than the sum of its proper divisors (118565999).

1991436049 is a wasteful number, since it uses less digits than its factorization.

1991436049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79055.

The product of its (nonzero) digits is 209952, while the sum is 46.

The square root of 1991436049 is about 44625.5089494787. The cubic root of 1991436049 is about 1258.1201599657.

The spelling of 1991436049 in words is "one billion, nine hundred ninety-one million, four hundred thirty-six thousand, forty-nine".