19315378681 has 4 divisors (see below), whose sum is σ = 19492584100. Its totient is φ = 19138173264.

The previous prime is 19315378637. The next prime is 19315378711. The reversal of 19315378681 is 18687351391.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18687351391 = 7669 ⋅2436739.

It can be written as a sum of positive squares in 2 ways, for example, as 16004527081 + 3310851600 = 126509^2 + 57540^2 .

It is a cyclic number.

It is not a de Polignac number, because 19315378681 - 2⁷ = 19315378553 is a prime.

It is a super-3 number, since 3×19315378681³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19315373681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88602546 + ... + 88602763.

It is an arithmetic number, because the mean of its divisors is an integer number (4873146025).

Almost surely, 2^19315378681 is an apocalyptic number.

It is an amenable number.

19315378681 is a deficient number, since it is larger than the sum of its proper divisors (177205419).

19315378681 is a wasteful number, since it uses less digits than its factorization.

19315378681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177205418.

The product of its digits is 1088640, while the sum is 52.

The spelling of 19315378681 in words is "nineteen billion, three hundred fifteen million, three hundred seventy-eight thousand, six hundred eighty-one".