2121219978 has 32 divisors (see below), whose sum is σ = 4354756992. Its totient is φ = 688584000.

The previous prime is 2121219977. The next prime is 2121220081. The reversal of 2121219978 is 8799121212.

It is not an unprimeable number, because it can be changed into a prime (2121219977) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8275 + ... + 65657.

It is an arithmetic number, because the mean of its divisors is an integer number (136086156).

Almost surely, 2^2121219978 is an apocalyptic number.

2121219978 is an abundant number, since it is smaller than the sum of its proper divisors (2233537014).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2121219978 is a wasteful number, since it uses less digits than its factorization.

2121219978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57550.

The product of its digits is 36288, while the sum is 42.

The square root of 2121219978 is about 46056.7039419887. The cubic root of 2121219978 is about 1284.8780290696.

The spelling of 2121219978 in words is "two billion, one hundred twenty-one million, two hundred nineteen thousand, nine hundred seventy-eight".