3973928221 has 2 divisors, whose sum is σ = 3973928222. Its totient is φ = 3973928220.

The previous prime is 3973928219. The next prime is 3973928227. The reversal of 3973928221 is 1228293793.

3973928221 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3892387321 + 81540900 = 62389^2 + 9030^2 .

It is a cyclic number.

It is not a de Polignac number, because 3973928221 - 2¹ = 3973928219 is a prime.

Together with 3973928219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3973928227) 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 as a sum of consecutive naturals, namely, 1986964110 + 1986964111.

It is an arithmetic number, because the mean of its divisors is an integer number (1986964111).

Almost surely, 2^3973928221 is an apocalyptic number.

It is an amenable number.

3973928221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3973928221 is an equidigital number, since it uses as much as digits as its factorization.

3973928221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 46.

The square root of 3973928221 is about 63039.1007312128. The cubic root of 3973928221 is about 1583.9446674302.

The spelling of 3973928221 in words is "three billion, nine hundred seventy-three million, nine hundred twenty-eight thousand, two hundred twenty-one".