19105381217 has 6 divisors (see below), whose sum is σ = 20688075702. Its totient is φ = 17635736352.

The previous prime is 19105381171. The next prime is 19105381219. The reversal of 19105381217 is 71218350191.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 2576679121 + 16528702096 = 50761^2 + 128564^2 .

It is not a de Polignac number, because 19105381217 - 2⁸ = 19105380961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19105381219) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 56524628 + ... + 56524965.

It is an arithmetic number, because the mean of its divisors is an integer number (3448012617).

Almost surely, 2^19105381217 is an apocalyptic number.

It is an amenable number.

19105381217 is a deficient number, since it is larger than the sum of its proper divisors (1582694485).

19105381217 is a wasteful number, since it uses less digits than its factorization.

19105381217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113049619 (or 113049606 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 38.

The spelling of 19105381217 in words is "nineteen billion, one hundred five million, three hundred eighty-one thousand, two hundred seventeen".