2721661765993 has 2 divisors, whose sum is σ = 2721661765994. Its totient is φ = 2721661765992.

The previous prime is 2721661765973. The next prime is 2721661766011. The reversal of 2721661765993 is 3995671661272.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1904170926889 + 817490839104 = 1379917^2 + 904152^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2721661765993 is a prime.

It is not a weakly prime, because it can be changed into another prime (2721661765903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1360830882996 + 1360830882997.

It is an arithmetic number, because the mean of its divisors is an integer number (1360830882997).

Almost surely, 2^{2721661765993} is an apocalyptic number.

It is an amenable number.

2721661765993 is a deficient number, since it is larger than the sum of its proper divisors (1).

2721661765993 is an equidigital number, since it uses as much as digits as its factorization.

2721661765993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51438240, while the sum is 64.

The spelling of 2721661765993 in words is "two trillion, seven hundred twenty-one billion, six hundred sixty-one million, seven hundred sixty-five thousand, nine hundred ninety-three".