1644724401 has 16 divisors (see below), whose sum is σ = 2204021760. Its totient is φ = 1090967760.

The previous prime is 1644724391. The next prime is 1644724409. The reversal of 1644724401 is 1044274461.

It is not a de Polignac number, because 1644724401 - 2¹⁹ = 1644200113 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1644724409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 874380 + ... + 876258.

It is an arithmetic number, because the mean of its divisors is an integer number (137751360).

Almost surely, 2^1644724401 is an apocalyptic number.

It is an amenable number.

1644724401 is a deficient number, since it is larger than the sum of its proper divisors (559297359).

1644724401 is a wasteful number, since it uses less digits than its factorization.

1644724401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3196.

The product of its (nonzero) digits is 21504, while the sum is 33.

The square root of 1644724401 is about 40555.2018981536. The cubic root of 1644724401 is about 1180.4050129866.

Adding to 1644724401 its reverse (1044274461), we get a palindrome (2688998862).

The spelling of 1644724401 in words is "one billion, six hundred forty-four million, seven hundred twenty-four thousand, four hundred one".