81855874419 has 16 divisors (see below), whose sum is σ = 119075201280. Its totient is φ = 49604574560.

The previous prime is 81855874409. The next prime is 81855874421. The reversal of 81855874419 is 91447855818.

It is a cyclic number.

It is not a de Polignac number, because 81855874419 - 2¹² = 81855870323 is a prime.

It is a super-2 number, since 2×81855874419² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81855874409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 217117 + ... + 459185.

It is an arithmetic number, because the mean of its divisors is an integer number (7442200080).

Almost surely, 2^81855874419 is an apocalyptic number.

81855874419 is a deficient number, since it is larger than the sum of its proper divisors (37219326861).

81855874419 is a wasteful number, since it uses less digits than its factorization.

81855874419 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252330.

The product of its digits is 12902400, while the sum is 60.

The spelling of 81855874419 in words is "eighty-one billion, eight hundred fifty-five million, eight hundred seventy-four thousand, four hundred nineteen".