20155354340646 has 96 divisors (see below), whose sum is σ = 48416481008640. Its totient is φ = 5571552168000.

The previous prime is 20155354340633. The next prime is 20155354340651. The reversal of 20155354340646 is 64604345355102.

It is a junction number, because it is equal to n+sod(n) for n = 20155354340595 and 20155354340604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 37455696 + ... + 37989996.

It is an arithmetic number, because the mean of its divisors is an integer number (504338343840).

Almost surely, 2^{20155354340646} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20155354340646, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24208240504320).

20155354340646 is an abundant number, since it is smaller than the sum of its proper divisors (28261126667994).

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

20155354340646 is a wasteful number, since it uses less digits than its factorization.

20155354340646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538490 (or 538483 counting only the distinct ones).

The product of its (nonzero) digits is 5184000, while the sum is 48.

Adding to 20155354340646 its reverse (64604345355102), we get a palindrome (84759699695748).

The spelling of 20155354340646 in words is "twenty trillion, one hundred fifty-five billion, three hundred fifty-four million, three hundred forty thousand, six hundred forty-six".