840005978 has 16 divisors (see below), whose sum is σ = 1443610944. Its totient is φ = 359102400.

The previous prime is 840005927. The next prime is 840005983. The reversal of 840005978 is 879500048.

It is a super-2 number, since 2×840005978² = 1411220086151472968, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69200 + ... + 80427.

It is an arithmetic number, because the mean of its divisors is an integer number (90225684).

Almost surely, 2^840005978 is an apocalyptic number.

840005978 is a deficient number, since it is larger than the sum of its proper divisors (603604966).

840005978 is a wasteful number, since it uses less digits than its factorization.

840005978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150037.

The product of its (nonzero) digits is 80640, while the sum is 41.

The square root of 840005978 is about 28982.8566224932. The cubic root of 840005978 is about 943.5410343417.

The spelling of 840005978 in words is "eight hundred forty million, five thousand, nine hundred seventy-eight".