1991604521852 has 48 divisors (see below), whose sum is σ = 3892399799904. Its totient is φ = 884033280000.

The previous prime is 1991604521789. The next prime is 1991604521861. The reversal of 1991604521852 is 2581254061991.

It is a super-2 number, since 2×1991604521852² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1991604521794 and 1991604521803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2745149 + ... + 3393972.

It is an arithmetic number, because the mean of its divisors is an integer number (81091662498).

Almost surely, 2^{1991604521852} is an apocalyptic number.

It is an amenable number.

1991604521852 is a deficient number, since it is larger than the sum of its proper divisors (1900795278052).

1991604521852 is a wasteful number, since it uses less digits than its factorization.

1991604521852 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6139310 (or 6139308 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 53.

The spelling of 1991604521852 in words is "one trillion, nine hundred ninety-one billion, six hundred four million, five hundred twenty-one thousand, eight hundred fifty-two".