3218433721 has 2 divisors, whose sum is σ = 3218433722. Its totient is φ = 3218433720.

The previous prime is 3218433697. The next prime is 3218433767. The reversal of 3218433721 is 1273348123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1989160000 + 1229273721 = 44600^2 + 35061^2 .

It is a cyclic number.

It is not a de Polignac number, because 3218433721 - 2⁵ = 3218433689 is a prime.

It is not a weakly prime, because it can be changed into another prime (3218433791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1609216860 + 1609216861.

It is an arithmetic number, because the mean of its divisors is an integer number (1609216861).

Almost surely, 2^3218433721 is an apocalyptic number.

It is an amenable number.

3218433721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3218433721 is an equidigital number, since it uses as much as digits as its factorization.

3218433721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 34.

The square root of 3218433721 is about 56731.2411374897. The cubic root of 3218433721 is about 1476.4367838047.

The spelling of 3218433721 in words is "three billion, two hundred eighteen million, four hundred thirty-three thousand, seven hundred twenty-one".