20363865617956 has 81 divisors (see below), whose sum is σ = 41899398205329. Its totient is φ = 8634798805248.

The previous prime is 20363865617939. The next prime is 20363865617957. The reversal of 20363865617956 is 65971656836302.

The square root of 20363865617956 is 4512634.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 9144152644900 + 11219712973056 = 3023930^2 + 3349584^2 .

It is a super-3 number, since 3×20363865617956³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20363865617891 and 20363865617900.

It is not an unprimeable number, because it can be changed into a prime (20363865617957) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 6128155311 + ... + 6128158633.

Almost surely, 2^{20363865617956} is an apocalyptic number.

20363865617956 is the 4512634-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20363865617956

20363865617956 is an abundant number, since it is smaller than the sum of its proper divisors (21535532587373).

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

20363865617956 is an frugal number, since it uses more digits than its factorization.

20363865617956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6858 (or 3429 counting only the distinct ones).

The product of its (nonzero) digits is 293932800, while the sum is 67.

The spelling of 20363865617956 in words is "twenty trillion, three hundred sixty-three billion, eight hundred sixty-five million, six hundred seventeen thousand, nine hundred fifty-six".