3968521 has 2 divisors, whose sum is σ = 3968522. Its totient is φ = 3968520.

The previous prime is 3968507. The next prime is 3968533. The reversal of 3968521 is 1258693.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3222025 + 746496 = 1795^2 + 864^2 .

It is a cyclic number.

It is not a de Polignac number, because 3968521 - 2⁹ = 3968009 is a prime.

3968521 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (3968501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1984260 + 1984261.

It is an arithmetic number, because the mean of its divisors is an integer number (1984261).

Almost surely, 2^3968521 is an apocalyptic number.

It is an amenable number.

3968521 is a deficient number, since it is larger than the sum of its proper divisors (1).

3968521 is an equidigital number, since it uses as much as digits as its factorization.

3968521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 34.

The square root of 3968521 is about 1992.1147055328. The cubic root of 3968521 is about 158.3225930542.

It can be divided in two parts, 3968 and 521, that added together give a square (4489 = 67²).

The spelling of 3968521 in words is "three million, nine hundred sixty-eight thousand, five hundred twenty-one".