1991361641107 has 6 divisors (see below), whose sum is σ = 2015643020972. Its totient is φ = 1967369325372.

The previous prime is 1991361641089. The next prime is 1991361641111. The reversal of 1991361641107 is 7011461631991.

It is a happy number.

It is not a de Polignac number, because 1991361641107 - 2¹⁹ = 1991361116819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1991361641177) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 144525093 + ... + 144538870.

Almost surely, 2^{1991361641107} is an apocalyptic number.

1991361641107 is a deficient number, since it is larger than the sum of its proper divisors (24281379865).

1991361641107 is an frugal number, since it uses more digits than its factorization.

1991361641107 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289064129 (or 289064046 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 49.

The spelling of 1991361641107 in words is "one trillion, nine hundred ninety-one billion, three hundred sixty-one million, six hundred forty-one thousand, one hundred seven".