1991719057737 has 16 divisors (see below), whose sum is σ = 2672108326080. Its totient is φ = 1319596185600.

The previous prime is 1991719057709. The next prime is 1991719057759. The reversal of 1991719057737 is 7377509171991.

It is not a de Polignac number, because 1991719057737 - 2¹⁰ = 1991719056713 is a prime.

It is a super-2 number, since 2×1991719057737² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1991719057787) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2797464 + ... + 3436457.

It is an arithmetic number, because the mean of its divisors is an integer number (167006770380).

Almost surely, 2^{1991719057737} is an apocalyptic number.

It is an amenable number.

1991719057737 is a deficient number, since it is larger than the sum of its proper divisors (680389268343).

1991719057737 is a wasteful number, since it uses less digits than its factorization.

1991719057737 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6234584.

The product of its (nonzero) digits is 26254935, while the sum is 66.

The spelling of 1991719057737 in words is "one trillion, nine hundred ninety-one billion, seven hundred nineteen million, fifty-seven thousand, seven hundred thirty-seven".