1720121953860 has 72 divisors (see below), whose sum is σ = 5217810428376. Its totient is φ = 458689766400.

The previous prime is 1720121953859. The next prime is 1720121953903. The reversal of 1720121953860 is 683591210271.

1720121953860 is a `hidden beast` number, since 1 + 72 + 0 + 12 + 195 + 386 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 90562476096 + 1629559477764 = 300936^2 + 1276542^2 .

It is a super-2 number, since 2×1720121953860² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16052460 + ... + 16159260.

It is an arithmetic number, because the mean of its divisors is an integer number (72469589283).

Almost surely, 2^{1720121953860} is an apocalyptic number.

1720121953860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1720121953860 is an abundant number, since it is smaller than the sum of its proper divisors (3497688474516).

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

1720121953860 is a wasteful number, since it uses less digits than its factorization.

1720121953860 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196293 (or 196288 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The spelling of 1720121953860 in words is "one trillion, seven hundred twenty billion, one hundred twenty-one million, nine hundred fifty-three thousand, eight hundred sixty".