1644063401 has 4 divisors (see below), whose sum is σ = 1647987600. Its totient is φ = 1640139204.

The previous prime is 1644063373. The next prime is 1644063409. The reversal of 1644063401 is 1043604461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1644063401 - 2¹⁴ = 1644047017 is a prime.

It is a super-3 number, since 3×1644063401³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1644063409) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1961471 + ... + 1962308.

It is an arithmetic number, because the mean of its divisors is an integer number (411996900).

Almost surely, 2^1644063401 is an apocalyptic number.

It is an amenable number.

1644063401 is a deficient number, since it is larger than the sum of its proper divisors (3924199).

1644063401 is an equidigital number, since it uses as much as digits as its factorization.

1644063401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3924198.

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 1644063401 is about 40547.0516930639. The cubic root of 1644063401 is about 1180.2468603986.

Adding to 1644063401 its reverse (1043604461), we get a palindrome (2687667862).

The spelling of 1644063401 in words is "one billion, six hundred forty-four million, sixty-three thousand, four hundred one".