19899357481 has 2 divisors, whose sum is σ = 19899357482. Its totient is φ = 19899357480.

The previous prime is 19899357473. The next prime is 19899357553. The reversal of 19899357481 is 18475399891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19275157225 + 624200256 = 138835^2 + 24984^2 .

It is a cyclic number.

It is not a de Polignac number, because 19899357481 - 2³ = 19899357473 is a prime.

It is a super-2 number, since 2×19899357481² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19899357451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9949678740 + 9949678741.

It is an arithmetic number, because the mean of its divisors is an integer number (9949678741).

Almost surely, 2^19899357481 is an apocalyptic number.

It is an amenable number.

19899357481 is a deficient number, since it is larger than the sum of its proper divisors (1).

19899357481 is an equidigital number, since it uses as much as digits as its factorization.

19899357481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19595520, while the sum is 64.

The spelling of 19899357481 in words is "nineteen billion, eight hundred ninety-nine million, three hundred fifty-seven thousand, four hundred eighty-one".