4021518778 has 8 divisors (see below), whose sum is σ = 6039319572. Its totient is φ = 2008412256.

The previous prime is 4021518773. The next prime is 4021518821. The reversal of 4021518778 is 8778151204.

It can be written as a sum of positive squares in 2 ways, for example, as 3978707929 + 42810849 = 63077^2 + 6543^2 .

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

It is a super-2 number, since 2×4021518778² = 32345226563613226568, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (4021518773) by changing a digit.

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, 1171425 + ... + 1174852.

Almost surely, 2^4021518778 is an apocalyptic number.

4021518778 is a deficient number, since it is larger than the sum of its proper divisors (2017800794).

4021518778 is a wasteful number, since it uses less digits than its factorization.

4021518778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2347136.

The product of its (nonzero) digits is 125440, while the sum is 43.

The square root of 4021518778 is about 63415.4458945137. The cubic root of 4021518778 is about 1590.2425401668.

The spelling of 4021518778 in words is "four billion, twenty-one million, five hundred eighteen thousand, seven hundred seventy-eight".