3786391921 has 8 divisors (see below), whose sum is σ = 4154590440. Its totient is φ = 3429184512.

The previous prime is 3786391907. The next prime is 3786391927. The reversal of 3786391921 is 1291936873.

It can be written as a sum of positive squares in 4 ways, for example, as 1262736225 + 2523655696 = 35535^2 + 50236^2 .

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

It is not a de Polignac number, because 3786391921 - 2¹³ = 3786383729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3786391927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2747056 + ... + 2748433.

It is an arithmetic number, because the mean of its divisors is an integer number (519323805).

Almost surely, 2^3786391921 is an apocalyptic number.

It is an amenable number.

3786391921 is a deficient number, since it is larger than the sum of its proper divisors (368198519).

3786391921 is a wasteful number, since it uses less digits than its factorization.

3786391921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5495555.

The product of its digits is 489888, while the sum is 49.

The square root of 3786391921 is about 61533.6649404210. The cubic root of 3786391921 is about 1558.6257787489.

The spelling of 3786391921 in words is "three billion, seven hundred eighty-six million, three hundred ninety-one thousand, nine hundred twenty-one".