1644064217 has 2 divisors, whose sum is σ = 1644064218. Its totient is φ = 1644064216.

The previous prime is 1644064211. The next prime is 1644064223. The reversal of 1644064217 is 7124604461.

It is a balanced prime because it is at equal distance from previous prime (1644064211) and next prime (1644064223).

It can be written as a sum of positive squares in only one way, i.e., 1170392521 + 473671696 = 34211^2 + 21764^2 .

It is a cyclic number.

It is not a de Polignac number, because 1644064217 - 2²⁰ = 1643015641 is a prime.

It is a super-3 number, since 3×1644064217³ (a number of 29 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1644064211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822032108 + 822032109.

It is an arithmetic number, because the mean of its divisors is an integer number (822032109).

Almost surely, 2^1644064217 is an apocalyptic number.

It is an amenable number.

1644064217 is a deficient number, since it is larger than the sum of its proper divisors (1).

1644064217 is an equidigital number, since it uses as much as digits as its factorization.

1644064217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32256, while the sum is 35.

The square root of 1644064217 is about 40547.0617554466. The cubic root of 1644064217 is about 1180.2470556631.

Adding to 1644064217 its reverse (7124604461), we get a palindrome (8768668678).

The spelling of 1644064217 in words is "one billion, six hundred forty-four million, sixty-four thousand, two hundred seventeen".