1644379229 has 2 divisors, whose sum is σ = 1644379230. Its totient is φ = 1644379228.

The previous prime is 1644379207. The next prime is 1644379249. The reversal of 1644379229 is 9229734461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1644302500 + 76729 = 40550^2 + 277^2 .

It is an emirp because it is prime and its reverse (9229734461) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1644379229 is a prime.

It is a super-3 number, since 3×1644379229³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1644379249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822189614 + 822189615.

It is an arithmetic number, because the mean of its divisors is an integer number (822189615).

Almost surely, 2^1644379229 is an apocalyptic number.

It is an amenable number.

1644379229 is a deficient number, since it is larger than the sum of its proper divisors (1).

1644379229 is an equidigital number, since it uses as much as digits as its factorization.

1644379229 is an evil number, because the sum of its binary digits is even.

The product of its digits is 653184, while the sum is 47.

The square root of 1644379229 is about 40550.9460925390. The cubic root of 1644379229 is about 1180.3224315189.

The spelling of 1644379229 in words is "one billion, six hundred forty-four million, three hundred seventy-nine thousand, two hundred twenty-nine".