19927605641 has 2 divisors, whose sum is σ = 19927605642. Its totient is φ = 19927605640.

The previous prime is 19927605619. The next prime is 19927605661. The reversal of 19927605641 is 14650672991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19819008400 + 108597241 = 140780^2 + 10421^2 .

It is an emirp because it is prime and its reverse (14650672991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19927605641 - 2¹⁴ = 19927589257 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19927605641.

It is not a weakly prime, because it can be changed into another prime (19927605661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9963802820 + 9963802821.

It is an arithmetic number, because the mean of its divisors is an integer number (9963802821).

Almost surely, 2^19927605641 is an apocalyptic number.

It is an amenable number.

19927605641 is a deficient number, since it is larger than the sum of its proper divisors (1).

19927605641 is an equidigital number, since it uses as much as digits as its factorization.

19927605641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 816480, while the sum is 50.

The spelling of 19927605641 in words is "nineteen billion, nine hundred twenty-seven million, six hundred five thousand, six hundred forty-one".