1720661260356 has 96 divisors (see below), whose sum is σ = 4591570618880. Its totient is φ = 556830588672.

The previous prime is 1720661260309. The next prime is 1720661260379. The reversal of 1720661260356 is 6530621660271.

1720661260356 is a `hidden beast` number, since 1 + 7 + 20 + 6 + 6 + 12 + 603 + 5 + 6 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1355061 + ... + 2297283.

Almost surely, 2^{1720661260356} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1720661260356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2295785309440).

1720661260356 is an abundant number, since it is smaller than the sum of its proper divisors (2870909358524).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1720661260356 is a wasteful number, since it uses less digits than its factorization.

1720661260356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 942730 (or 942722 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The spelling of 1720661260356 in words is "one trillion, seven hundred twenty billion, six hundred sixty-one million, two hundred sixty thousand, three hundred fifty-six".