84173912891 has 4 divisors (see below), whose sum is σ = 84214247472. Its totient is φ = 84133578312.

The previous prime is 84173912873. The next prime is 84173912929. The reversal of 84173912891 is 19821937148.

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

It is a cyclic number.

It is not a de Polignac number, because 84173912891 - 2¹⁸ = 84173650747 is a prime.

It is a super-2 number, since 2×84173912891² (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 (84173972891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20164160 + ... + 20168333.

It is an arithmetic number, because the mean of its divisors is an integer number (21053561868).

Almost surely, 2^84173912891 is an apocalyptic number.

84173912891 is a deficient number, since it is larger than the sum of its proper divisors (40334581).

84173912891 is a wasteful number, since it uses less digits than its factorization.

84173912891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40334580.

The product of its digits is 870912, while the sum is 53.

The spelling of 84173912891 in words is "eighty-four billion, one hundred seventy-three million, nine hundred twelve thousand, eight hundred ninety-one".