81768837919 has 8 divisors (see below), whose sum is σ = 85013788160. Its totient is φ = 78561840600.

The previous prime is 81768837907. The next prime is 81768837959. The reversal of 81768837919 is 91973886718.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81768837919 - 2¹⁷ = 81768706847 is a prime.

It is a super-2 number, since 2×81768837919² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81768837959) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9483837 + ... + 9492454.

It is an arithmetic number, because the mean of its divisors is an integer number (10626723520).

Almost surely, 2^81768837919 is an apocalyptic number.

81768837919 is a deficient number, since it is larger than the sum of its proper divisors (3244950241).

81768837919 is a wasteful number, since it uses less digits than its factorization.

81768837919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18976461.

The product of its digits is 36578304, while the sum is 67.

The spelling of 81768837919 in words is "eighty-one billion, seven hundred sixty-eight million, eight hundred thirty-seven thousand, nine hundred nineteen".