21354612716761 has 2 divisors, whose sum is σ = 21354612716762. Its totient is φ = 21354612716760.

The previous prime is 21354612716753. The next prime is 21354612716803. The reversal of 21354612716761 is 16761721645312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18801069440400 + 2553543276361 = 4336020^2 + 1597981^2 .

It is a cyclic number.

It is not a de Polignac number, because 21354612716761 - 2³ = 21354612716753 is a prime.

It is a super-2 number, since 2×21354612716761² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21354612716699 and 21354612716708.

It is not a weakly prime, because it can be changed into another prime (21354612716711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10677306358380 + 10677306358381.

It is an arithmetic number, because the mean of its divisors is an integer number (10677306358381).

Almost surely, 2^{21354612716761} is an apocalyptic number.

It is an amenable number.

21354612716761 is a deficient number, since it is larger than the sum of its proper divisors (1).

21354612716761 is an equidigital number, since it uses as much as digits as its factorization.

21354612716761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2540160, while the sum is 52.

The spelling of 21354612716761 in words is "twenty-one trillion, three hundred fifty-four billion, six hundred twelve million, seven hundred sixteen thousand, seven hundred sixty-one".