1601644321 has 2 divisors, whose sum is σ = 1601644322. Its totient is φ = 1601644320.

The previous prime is 1601644279. The next prime is 1601644327. The reversal of 1601644321 is 1234461061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 841870225 + 759774096 = 29015^2 + 27564^2 .

It is a cyclic number.

It is not a de Polignac number, because 1601644321 - 2⁹ = 1601643809 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1601644321.

It is not a weakly prime, because it can be changed into another prime (1601644327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 800822160 + 800822161.

It is an arithmetic number, because the mean of its divisors is an integer number (800822161).

Almost surely, 2^1601644321 is an apocalyptic number.

It is an amenable number.

1601644321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1601644321 is an equidigital number, since it uses as much as digits as its factorization.

1601644321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 1601644321 is about 40020.5487343689. The cubic root of 1601644321 is about 1170.0076267553.

The spelling of 1601644321 in words is "one billion, six hundred one million, six hundred forty-four thousand, three hundred twenty-one".