3872159975821 has 2 divisors, whose sum is σ = 3872159975822. Its totient is φ = 3872159975820.

The previous prime is 3872159975777. The next prime is 3872159975891. The reversal of 3872159975821 is 1285799512783.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3763483600900 + 108676374921 = 1939970^2 + 329661^2 .

It is an emirp because it is prime and its reverse (1285799512783) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3872159975821 - 2¹⁹ = 3872159451533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3872159975891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1936079987910 + 1936079987911.

It is an arithmetic number, because the mean of its divisors is an integer number (1936079987911).

Almost surely, 2^{3872159975821} is an apocalyptic number.

It is an amenable number.

3872159975821 is a deficient number, since it is larger than the sum of its proper divisors (1).

3872159975821 is an equidigital number, since it uses as much as digits as its factorization.

3872159975821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 76204800, while the sum is 67.

The spelling of 3872159975821 in words is "three trillion, eight hundred seventy-two billion, one hundred fifty-nine million, nine hundred seventy-five thousand, eight hundred twenty-one".