84391979 has 4 divisors (see below), whose sum is σ = 96447984. Its totient is φ = 72335976.

The previous prime is 84391963. The next prime is 84391997. The reversal of 84391979 is 97919348.

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 84391979 - 2⁴ = 84391963 is a prime.

It is a super-3 number, since 3×84391979³ (a number of 25 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 (84391919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6027992 + ... + 6028005.

It is an arithmetic number, because the mean of its divisors is an integer number (24111996).

Almost surely, 2^84391979 is an apocalyptic number.

84391979 is a deficient number, since it is larger than the sum of its proper divisors (12056005).

84391979 is a wasteful number, since it uses less digits than its factorization.

84391979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12056004.

The product of its digits is 489888, while the sum is 50.

The square root of 84391979 is about 9186.5107086423. The cubic root of 84391979 is about 438.6320791422.

The spelling of 84391979 in words is "eighty-four million, three hundred ninety-one thousand, nine hundred seventy-nine".