19663462421 has 2 divisors, whose sum is σ = 19663462422. Its totient is φ = 19663462420.

The previous prime is 19663462397. The next prime is 19663462453. The reversal of 19663462421 is 12426436691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13465049521 + 6198412900 = 116039^2 + 78730^2 .

It is an emirp because it is prime and its reverse (12426436691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19663462421 - 2¹⁴ = 19663446037 is a prime.

It is a super-3 number, since 3×19663462421³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19663465421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9831731210 + 9831731211.

It is an arithmetic number, because the mean of its divisors is an integer number (9831731211).

Almost surely, 2^19663462421 is an apocalyptic number.

It is an amenable number.

19663462421 is a deficient number, since it is larger than the sum of its proper divisors (1).

19663462421 is an equidigital number, since it uses as much as digits as its factorization.

19663462421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 373248, while the sum is 44.

The spelling of 19663462421 in words is "nineteen billion, six hundred sixty-three million, four hundred sixty-two thousand, four hundred twenty-one".