81338769419 has 4 divisors (see below), whose sum is σ = 81341641344. Its totient is φ = 81335897496.

The previous prime is 81338769409. The next prime is 81338769443. The reversal of 81338769419 is 91496783318.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91496783318 = 2 ⋅45748391659.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81338769419 is a prime.

It is a super-2 number, since 2×81338769419² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81338769409) 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, 1393052 + ... + 1450265.

It is an arithmetic number, because the mean of its divisors is an integer number (20335410336).

Almost surely, 2^81338769419 is an apocalyptic number.

81338769419 is a deficient number, since it is larger than the sum of its proper divisors (2871925).

81338769419 is a wasteful number, since it uses less digits than its factorization.

81338769419 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2871924.

The product of its digits is 7838208, while the sum is 59.

The spelling of 81338769419 in words is "eighty-one billion, three hundred thirty-eight million, seven hundred sixty-nine thousand, four hundred nineteen".