20612727721 has 2 divisors, whose sum is σ = 20612727722. Its totient is φ = 20612727720.

The previous prime is 20612727703. The next prime is 20612727827. The reversal of 20612727721 is 12772721602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20323353600 + 289374121 = 142560^2 + 17011^2 .

It is a cyclic number.

It is not a de Polignac number, because 20612727721 - 2⁵ = 20612727689 is a prime.

It is not a weakly prime, because it can be changed into another prime (20612722721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10306363860 + 10306363861.

It is an arithmetic number, because the mean of its divisors is an integer number (10306363861).

Almost surely, 2^20612727721 is an apocalyptic number.

It is an amenable number.

20612727721 is a deficient number, since it is larger than the sum of its proper divisors (1).

20612727721 is an equidigital number, since it uses as much as digits as its factorization.

20612727721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32928, while the sum is 37.

The spelling of 20612727721 in words is "twenty billion, six hundred twelve million, seven hundred twenty-seven thousand, seven hundred twenty-one".