165197937413891 has 4 divisors (see below), whose sum is σ = 170894418014400. Its totient is φ = 159501456813384.

The previous prime is 165197937413881. The next prime is 165197937413963. The reversal of 165197937413891 is 198314739791561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165197937413891 - 2¹⁰ = 165197937412867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165197937413881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2848240300211 + ... + 2848240300268.

It is an arithmetic number, because the mean of its divisors is an integer number (42723604503600).

Almost surely, 2^{165197937413891} is an apocalyptic number.

165197937413891 is a deficient number, since it is larger than the sum of its proper divisors (5696480600509).

165197937413891 is an equidigital number, since it uses as much as digits as its factorization.

165197937413891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5696480600508.

The product of its digits is 308629440, while the sum is 74.

The spelling of 165197937413891 in words is "one hundred sixty-five trillion, one hundred ninety-seven billion, nine hundred thirty-seven million, four hundred thirteen thousand, eight hundred ninety-one".