4021978 has 8 divisors (see below), whose sum is σ = 6161472. Its totient is φ = 1968156.

The previous prime is 4021973. The next prime is 4022003. The reversal of 4021978 is 8791204.

It is a sphenic number, since it is the product of 3 distinct primes.

4021978 is a modest number, since divided by 21978 gives 4 as remainder.

It is not an unprimeable number, because it can be changed into a prime (4021973) 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, 21300 + ... + 21487.

It is an arithmetic number, because the mean of its divisors is an integer number (770184).

Almost surely, 2^4021978 is an apocalyptic number.

4021978 is a deficient number, since it is larger than the sum of its proper divisors (2139494).

4021978 is a wasteful number, since it uses less digits than its factorization.

4021978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42836.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 4021978 is about 2005.4869732811. The cubic root of 4021978 is about 159.0303068424.

The spelling of 4021978 in words is "four million, twenty-one thousand, nine hundred seventy-eight".