4078388821 has 4 divisors (see below), whose sum is σ = 4392111052. Its totient is φ = 3764666592.

The previous prime is 4078388767. The next prime is 4078388837. The reversal of 4078388821 is 1288838704.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1052288721 + 3026100100 = 32439^2 + 55010^2 .

It is a cyclic number.

It is not a de Polignac number, because 4078388821 - 2⁷ = 4078388693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4078388891) 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 3 ways as a sum of consecutive naturals, for example, 156861096 + ... + 156861121.

It is an arithmetic number, because the mean of its divisors is an integer number (1098027763).

Almost surely, 2^4078388821 is an apocalyptic number.

It is an amenable number.

4078388821 is a deficient number, since it is larger than the sum of its proper divisors (313722231).

4078388821 is a wasteful number, since it uses less digits than its factorization.

4078388821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313722230.

The product of its (nonzero) digits is 688128, while the sum is 49.

The square root of 4078388821 is about 63862.2644524918. The cubic root of 4078388821 is about 1597.7035833553.

The spelling of 4078388821 in words is "four billion, seventy-eight million, three hundred eighty-eight thousand, eight hundred twenty-one".