3964981021 has 16 divisors (see below), whose sum is σ = 4053016576. Its totient is φ = 3878171136.

The previous prime is 3964981019. The next prime is 3964981049. The reversal of 3964981021 is 1201894693.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 3964981021 - 2¹ = 3964981019 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 (3964981051) 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, 4520635 + ... + 4521511.

It is an arithmetic number, because the mean of its divisors is an integer number (253313536).

Almost surely, 2^3964981021 is an apocalyptic number.

It is an amenable number.

3964981021 is a deficient number, since it is larger than the sum of its proper divisors (88035555).

3964981021 is a wasteful number, since it uses less digits than its factorization.

3964981021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1468.

The product of its (nonzero) digits is 93312, while the sum is 43.

The square root of 3964981021 is about 62968.0952626010. The cubic root of 3964981021 is about 1582.7550369073.

The spelling of 3964981021 in words is "three billion, nine hundred sixty-four million, nine hundred eighty-one thousand, twenty-one".