2001720571906 has 16 divisors (see below), whose sum is σ = 3279493981440. Its totient is φ = 908775424080.

The previous prime is 2001720571891. The next prime is 2001720571919. The reversal of 2001720571906 is 6091750271002.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54859506 + ... + 54895981.

It is an arithmetic number, because the mean of its divisors is an integer number (204968373840).

Almost surely, 2^{2001720571906} is an apocalyptic number.

2001720571906 is a deficient number, since it is larger than the sum of its proper divisors (1277773409534).

2001720571906 is a wasteful number, since it uses less digits than its factorization.

2001720571906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109756329.

The product of its (nonzero) digits is 52920, while the sum is 40.

The spelling of 2001720571906 in words is "two trillion, one billion, seven hundred twenty million, five hundred seventy-one thousand, nine hundred six".