1991700020885 has 32 divisors (see below), whose sum is σ = 2476064678400. Its totient is φ = 1536172485120.

The previous prime is 1991700020857. The next prime is 1991700020897. The reversal of 1991700020885 is 5880200071991.

It is a de Polignac number, because none of the positive numbers 2^k-1991700020885 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 557741150 + ... + 557744720.

It is an arithmetic number, because the mean of its divisors is an integer number (77377021200).

Almost surely, 2^{1991700020885} is an apocalyptic number.

It is an amenable number.

1991700020885 is a deficient number, since it is larger than the sum of its proper divisors (484364657515).

1991700020885 is a wasteful number, since it uses less digits than its factorization.

1991700020885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8141.

The product of its (nonzero) digits is 362880, while the sum is 50.

The spelling of 1991700020885 in words is "one trillion, nine hundred ninety-one billion, seven hundred million, twenty thousand, eight hundred eighty-five".