19283968721 has 2 divisors, whose sum is σ = 19283968722. Its totient is φ = 19283968720.

The previous prime is 19283968687. The next prime is 19283968733. The reversal of 19283968721 is 12786938291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11938621696 + 7345347025 = 109264^2 + 85705^2 .

It is a cyclic number.

It is not a de Polignac number, because 19283968721 - 2⁶ = 19283968657 is a prime.

It is not a weakly prime, because it can be changed into another prime (19282968721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9641984360 + 9641984361.

It is an arithmetic number, because the mean of its divisors is an integer number (9641984361).

Almost surely, 2^19283968721 is an apocalyptic number.

It is an amenable number.

19283968721 is a deficient number, since it is larger than the sum of its proper divisors (1).

19283968721 is an equidigital number, since it uses as much as digits as its factorization.

19283968721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2612736, while the sum is 56.

The spelling of 19283968721 in words is "nineteen billion, two hundred eighty-three million, nine hundred sixty-eight thousand, seven hundred twenty-one".