3900385021 has 16 divisors (see below), whose sum is σ = 4466977200. Its totient is φ = 3373728768.

The previous prime is 3900385009. The next prime is 3900385031. The reversal of 3900385021 is 1205830093.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 793548900 + 3106836121 = 28170^2 + 55739^2 .

It is a cyclic number.

It is not a de Polignac number, because 3900385021 - 2¹⁹ = 3899860733 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 (3900385031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12075 + ... + 89143.

It is an arithmetic number, because the mean of its divisors is an integer number (279186075).

Almost surely, 2^3900385021 is an apocalyptic number.

It is an amenable number.

3900385021 is a deficient number, since it is larger than the sum of its proper divisors (566592179).

3900385021 is a wasteful number, since it uses less digits than its factorization.

3900385021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77328.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 3900385021 is about 62453.0625430010. The cubic root of 3900385021 is about 1574.1127137738.

The spelling of 3900385021 in words is "three billion, nine hundred million, three hundred eighty-five thousand, twenty-one".