3878820021 has 8 divisors (see below), whose sum is σ = 5179447360. Its totient is φ = 2582036352.

The previous prime is 3878820017. The next prime is 3878820053. The reversal of 3878820021 is 1200288783.

3878820021 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 3878820021 - 2² = 3878820017 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 (3878820061) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 958561 + ... + 962598.

It is an arithmetic number, because the mean of its divisors is an integer number (647430920).

Almost surely, 2^3878820021 is an apocalyptic number.

It is an amenable number.

3878820021 is a deficient number, since it is larger than the sum of its proper divisors (1300627339).

3878820021 is a wasteful number, since it uses less digits than its factorization.

3878820021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1921835.

The product of its (nonzero) digits is 43008, while the sum is 39.

The square root of 3878820021 is about 62280.1735787562. The cubic root of 3878820021 is about 1571.2062917409.

The spelling of 3878820021 in words is "three billion, eight hundred seventy-eight million, eight hundred twenty thousand, twenty-one".