1985974795891 has 4 divisors (see below), whose sum is σ = 2005637912784. Its totient is φ = 1966311679000.

The previous prime is 1985974795873. The next prime is 1985974795907.

1985974795891 is nontrivially palindromic in base 10.

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 1985974795891 - 2¹¹ = 1985974793843 is a prime.

It is a super-2 number, since 2×1985974795891² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1985974735891) 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, 9831558295 + ... + 9831558496.

It is an arithmetic number, because the mean of its divisors is an integer number (501409478196).

Almost surely, 2^{1985974795891} is an apocalyptic number.

1985974795891 is a deficient number, since it is larger than the sum of its proper divisors (19663116893).

1985974795891 is a wasteful number, since it uses less digits than its factorization.

1985974795891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19663116892.

The product of its digits is 2057529600, while the sum is 82.

The spelling of 1985974795891 in words is "one trillion, nine hundred eighty-five billion, nine hundred seventy-four million, seven hundred ninety-five thousand, eight hundred ninety-one".