20705381744261 has 2 divisors, whose sum is σ = 20705381744262. Its totient is φ = 20705381744260.

The previous prime is 20705381744251. The next prime is 20705381744339. The reversal of 20705381744261 is 16244718350702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14352209441761 + 6353172302500 = 3788431^2 + 2520550^2 .

It is a cyclic number.

It is not a de Polignac number, because 20705381744261 - 2¹⁸ = 20705381482117 is a prime.

It is a super-2 number, since 2×20705381744261² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20705381744251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10352690872130 + 10352690872131.

It is an arithmetic number, because the mean of its divisors is an integer number (10352690872131).

Almost surely, 2^{20705381744261} is an apocalyptic number.

It is an amenable number.

20705381744261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20705381744261 is an equidigital number, since it uses as much as digits as its factorization.

20705381744261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2257920, while the sum is 50.

The spelling of 20705381744261 in words is "twenty trillion, seven hundred five billion, three hundred eighty-one million, seven hundred forty-four thousand, two hundred sixty-one".