2138781766 has 8 divisors (see below), whose sum is σ = 3499824744. Its totient is φ = 972173520.

The previous prime is 2138781731. The next prime is 2138781779. The reversal of 2138781766 is 6671878312.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48608655 + ... + 48608698.

It is an arithmetic number, because the mean of its divisors is an integer number (437478093).

Almost surely, 2^2138781766 is an apocalyptic number.

2138781766 is a deficient number, since it is larger than the sum of its proper divisors (1361042978).

2138781766 is a wasteful number, since it uses less digits than its factorization.

2138781766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97217366.

The product of its digits is 677376, while the sum is 49.

The square root of 2138781766 is about 46246.9649382530. The cubic root of 2138781766 is about 1288.4141653015.

The spelling of 2138781766 in words is "two billion, one hundred thirty-eight million, seven hundred eighty-one thousand, seven hundred sixty-six".