3778221691 has 2 divisors, whose sum is σ = 3778221692. Its totient is φ = 3778221690.

The previous prime is 3778221673. The next prime is 3778221719. The reversal of 3778221691 is 1961228773.

3778221691 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 3778221691 - 2⁵ = 3778221659 is a prime.

It is not a weakly prime, because it can be changed into another prime (3778221641) 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 as a sum of consecutive naturals, namely, 1889110845 + 1889110846.

It is an arithmetic number, because the mean of its divisors is an integer number (1889110846).

Almost surely, 2^3778221691 is an apocalyptic number.

3778221691 is a deficient number, since it is larger than the sum of its proper divisors (1).

3778221691 is an equidigital number, since it uses as much as digits as its factorization.

3778221691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 254016, while the sum is 46.

The square root of 3778221691 is about 61467.2407954026. The cubic root of 3778221691 is about 1557.5039102537.

The spelling of 3778221691 in words is "three billion, seven hundred seventy-eight million, two hundred twenty-one thousand, six hundred ninety-one".