2139441978 has 8 divisors (see below), whose sum is σ = 4278883968. Its totient is φ = 713147324.

The previous prime is 2139441977. The next prime is 2139442003. The reversal of 2139441978 is 8791449312.

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

2139441978 is an admirable number.

It is a super-3 number, since 3×2139441978³ (a number of 29 digits) contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2139441973) 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, 178286826 + ... + 178286837.

It is an arithmetic number, because the mean of its divisors is an integer number (534860496).

Almost surely, 2^2139441978 is an apocalyptic number.

2139441978 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

2139441978 is a wasteful number, since it uses less digits than its factorization.

2139441978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356573668.

The product of its digits is 435456, while the sum is 48.

The square root of 2139441978 is about 46254.1022829327. The cubic root of 2139441978 is about 1288.5467234702.

The spelling of 2139441978 in words is "two billion, one hundred thirty-nine million, four hundred forty-one thousand, nine hundred seventy-eight".