84905978 has 16 divisors (see below), whose sum is σ = 128812896. Its totient is φ = 41971440.

The previous prime is 84905971. The next prime is 84905983. The reversal of 84905978 is 87950948.

It is not an unprimeable number, because it can be changed into a prime (84905971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72425 + ... + 73587.

It is an arithmetic number, because the mean of its divisors is an integer number (8050806).

Almost surely, 2^84905978 is an apocalyptic number.

84905978 is a deficient number, since it is larger than the sum of its proper divisors (43906918).

84905978 is a wasteful number, since it uses less digits than its factorization.

84905978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1549.

The product of its (nonzero) digits is 725760, while the sum is 50.

The square root of 84905978 is about 9214.4439875665. The cubic root of 84905978 is about 439.5207902594.

The spelling of 84905978 in words is "eighty-four million, nine hundred five thousand, nine hundred seventy-eight".