2139918805 has 8 divisors (see below), whose sum is σ = 2572516152. Its totient is φ = 1708859328.

The previous prime is 2139918799. The next prime is 2139918821. The reversal of 2139918805 is 5088199312.

It can be written as a sum of positive squares in 4 ways, for example, as 20421361 + 2119497444 = 4519^2 + 46038^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 2139918805 - 2²⁵ = 2106364373 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 381402 + ... + 386971.

It is an arithmetic number, because the mean of its divisors is an integer number (321564519).

Almost surely, 2^2139918805 is an apocalyptic number.

It is an amenable number.

2139918805 is a deficient number, since it is larger than the sum of its proper divisors (432597347).

2139918805 is an equidigital number, since it uses as much as digits as its factorization.

2139918805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 768935.

The product of its (nonzero) digits is 155520, while the sum is 46.

The square root of 2139918805 is about 46259.2564250659. The cubic root of 2139918805 is about 1288.6424444159.

It can be divided in two parts, 21399 and 18805, that added together give a palindrome (40204).

The spelling of 2139918805 in words is "two billion, one hundred thirty-nine million, nine hundred eighteen thousand, eight hundred five".