3208721 has 2 divisors, whose sum is σ = 3208722. Its totient is φ = 3208720.

The previous prime is 3208693. The next prime is 3208727. The reversal of 3208721 is 1278023.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1918225 + 1290496 = 1385^2 + 1136^2 .

It is a cyclic number.

It is not a de Polignac number, because 3208721 - 2⁶ = 3208657 is a prime.

It is not a weakly prime, because it can be changed into another prime (3208727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1604360 + 1604361.

It is an arithmetic number, because the mean of its divisors is an integer number (1604361).

Almost surely, 2^3208721 is an apocalyptic number.

It is an amenable number.

3208721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3208721 is an equidigital number, since it uses as much as digits as its factorization.

3208721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 3208721 is about 1791.2903170620. The cubic root of 3208721 is about 147.4950070128.

The spelling of 3208721 in words is "three million, two hundred eight thousand, seven hundred twenty-one".