20355731161717 has 12 divisors (see below), whose sum is σ = 23679189331680. Its totient is φ = 17447715416376.

The previous prime is 20355731161693. The next prime is 20355731161757. The reversal of 20355731161717 is 71716113755302.

It is not a de Polignac number, because 20355731161717 - 2¹¹ = 20355731159669 is a prime.

It is a super-2 number, since 2×20355731161717² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20355731161757) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 30650584 + ... + 31307662.

It is an arithmetic number, because the mean of its divisors is an integer number (1973265777640).

Almost surely, 2^{20355731161717} is an apocalyptic number.

It is an amenable number.

20355731161717 is a deficient number, since it is larger than the sum of its proper divisors (3323458169963).

20355731161717 is an equidigital number, since it uses as much as digits as its factorization.

20355731161717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1289320 (or 1289313 counting only the distinct ones).

The product of its (nonzero) digits is 926100, while the sum is 49.

The spelling of 20355731161717 in words is "twenty trillion, three hundred fifty-five billion, seven hundred thirty-one million, one hundred sixty-one thousand, seven hundred seventeen".