19748763521 has 2 divisors, whose sum is σ = 19748763522. Its totient is φ = 19748763520.

The previous prime is 19748763499. The next prime is 19748763599. The reversal of 19748763521 is 12536784791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14193148225 + 5555615296 = 119135^2 + 74536^2 .

It is a cyclic number.

It is not a de Polignac number, because 19748763521 - 2¹⁰ = 19748762497 is a prime.

It is not a weakly prime, because it can be changed into another prime (19748723521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9874381760 + 9874381761.

It is an arithmetic number, because the mean of its divisors is an integer number (9874381761).

Almost surely, 2^19748763521 is an apocalyptic number.

It is an amenable number.

19748763521 is a deficient number, since it is larger than the sum of its proper divisors (1).

19748763521 is an equidigital number, since it uses as much as digits as its factorization.

19748763521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2540160, while the sum is 53.

The spelling of 19748763521 in words is "nineteen billion, seven hundred forty-eight million, seven hundred sixty-three thousand, five hundred twenty-one".