81606380419 has 4 divisors (see below), whose sum is σ = 81609196144. Its totient is φ = 81603564696.

The previous prime is 81606380347. The next prime is 81606380441. The reversal of 81606380419 is 91408360618.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81606380419 is a prime.

It is a super-3 number, since 3×81606380419³ (a number of 34 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 (81606380489) 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, 1363932 + ... + 1422505.

It is an arithmetic number, because the mean of its divisors is an integer number (20402299036).

Almost surely, 2^81606380419 is an apocalyptic number.

81606380419 is a deficient number, since it is larger than the sum of its proper divisors (2815725).

81606380419 is a wasteful number, since it uses less digits than its factorization.

81606380419 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2815724.

The product of its (nonzero) digits is 248832, while the sum is 46.

The spelling of 81606380419 in words is "eighty-one billion, six hundred six million, three hundred eighty thousand, four hundred nineteen".