19397879381 has 2 divisors, whose sum is σ = 19397879382. Its totient is φ = 19397879380.

The previous prime is 19397879377. The next prime is 19397879447. The reversal of 19397879381 is 18397879391.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19391955025 + 5924356 = 139255^2 + 2434^2 .

It is an emirp because it is prime and its reverse (18397879391) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19397879381 - 2² = 19397879377 is a prime.

It is a super-2 number, since 2×19397879381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19397879321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9698939690 + 9698939691.

It is an arithmetic number, because the mean of its divisors is an integer number (9698939691).

Almost surely, 2^19397879381 is an apocalyptic number.

It is an amenable number.

19397879381 is a deficient number, since it is larger than the sum of its proper divisors (1).

19397879381 is an equidigital number, since it uses as much as digits as its factorization.

19397879381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20575296, while the sum is 65.

The spelling of 19397879381 in words is "nineteen billion, three hundred ninety-seven million, eight hundred seventy-nine thousand, three hundred eighty-one".