1720121953845 has 8 divisors (see below), whose sum is σ = 2752195126176. Its totient is φ = 917398375376.

The previous prime is 1720121953819. The next prime is 1720121953859. The reversal of 1720121953845 is 5483591210271.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1720121953845 - 2³¹ = 1717974470197 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1720121953794 and 1720121953803.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 57337398447 + ... + 57337398476.

It is an arithmetic number, because the mean of its divisors is an integer number (344024390772).

Almost surely, 2^{1720121953845} is an apocalyptic number.

1720121953845 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1720121953845 is a deficient number, since it is larger than the sum of its proper divisors (1032073172331).

1720121953845 is a wasteful number, since it uses less digits than its factorization.

1720121953845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114674796931.

The product of its (nonzero) digits is 604800, while the sum is 48.

The spelling of 1720121953845 in words is "one trillion, seven hundred twenty billion, one hundred twenty-one million, nine hundred fifty-three thousand, eight hundred forty-five".