1644224794 has 4 divisors (see below), whose sum is σ = 2466337194. Its totient is φ = 822112396.

The previous prime is 1644224783. The next prime is 1644224821. The reversal of 1644224794 is 4974224461.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 4974224461 = 47 ⋅105834563.

It can be written as a sum of positive squares in only one way, i.e., 1269995769 + 374229025 = 35637^2 + 19345^2 .

It is a super-3 number, since 3×1644224794³ (a number of 29 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1644224794.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 411056197 + ... + 411056200.

Almost surely, 2^1644224794 is an apocalyptic number.

1644224794 is a deficient number, since it is larger than the sum of its proper divisors (822112400).

1644224794 is an equidigital number, since it uses as much as digits as its factorization.

1644224794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 822112399.

The product of its digits is 387072, while the sum is 43.

The square root of 1644224794 is about 40549.0418382482. The cubic root of 1644224794 is about 1180.2854796207.

The spelling of 1644224794 in words is "one billion, six hundred forty-four million, two hundred twenty-four thousand, seven hundred ninety-four".