1720661257105 has 64 divisors (see below), whose sum is σ = 2633272104960. Its totient is φ = 1050753199104.

The previous prime is 1720661257097. The next prime is 1720661257127. The reversal of 1720661257105 is 5017521660271.

It is not a de Polignac number, because 1720661257105 - 2³ = 1720661257097 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9257214 + ... + 9441256.

It is an arithmetic number, because the mean of its divisors is an integer number (41144876640).

Almost surely, 2^{1720661257105} is an apocalyptic number.

It is an amenable number.

1720661257105 is a deficient number, since it is larger than the sum of its proper divisors (912610847855).

1720661257105 is a wasteful number, since it uses less digits than its factorization.

1720661257105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184918.

The product of its (nonzero) digits is 176400, while the sum is 43.

The spelling of 1720661257105 in words is "one trillion, seven hundred twenty billion, six hundred sixty-one million, two hundred fifty-seven thousand, one hundred five".