20659611319961 has 2 divisors, whose sum is σ = 20659611319962. Its totient is φ = 20659611319960.

The previous prime is 20659611319883. The next prime is 20659611320027. The reversal of 20659611319961 is 16991311695602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20439612798361 + 219998521600 = 4521019^2 + 469040^2 .

It is a cyclic number.

It is not a de Polignac number, because 20659611319961 - 2¹⁴ = 20659611303577 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20659611319961.

It is not a weakly prime, because it can be changed into another prime (20659611379961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10329805659980 + 10329805659981.

It is an arithmetic number, because the mean of its divisors is an integer number (10329805659981).

Almost surely, 2^{20659611319961} is an apocalyptic number.

It is an amenable number.

20659611319961 is a deficient number, since it is larger than the sum of its proper divisors (1).

20659611319961 is an equidigital number, since it uses as much as digits as its factorization.

20659611319961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4723920, while the sum is 59.

The spelling of 20659611319961 in words is "twenty trillion, six hundred fifty-nine billion, six hundred eleven million, three hundred nineteen thousand, nine hundred sixty-one".