1644022013 has 4 divisors (see below), whose sum is σ = 1654909728. Its totient is φ = 1633134300.

The previous prime is 1644022007. The next prime is 1644022019. The reversal of 1644022013 is 3102204461.

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 an interprime number because it is at equal distance from previous prime (1644022007) and next prime (1644022019).

It is a cyclic number.

It is not a de Polignac number, because 1644022013 - 2⁴ = 1644021997 is a prime.

It is a super-3 number, since 3×1644022013³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1644022013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644022019) 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, 5443631 + ... + 5443932.

It is an arithmetic number, because the mean of its divisors is an integer number (413727432).

Almost surely, 2^1644022013 is an apocalyptic number.

It is an amenable number.

1644022013 is a deficient number, since it is larger than the sum of its proper divisors (10887715).

1644022013 is a wasteful number, since it uses less digits than its factorization.

1644022013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10887714.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 1644022013 is about 40546.5413198216. The cubic root of 1644022013 is about 1180.2369563874.

Adding to 1644022013 its reverse (3102204461), we get a palindrome (4746226474).

The spelling of 1644022013 in words is "one billion, six hundred forty-four million, twenty-two thousand, thirteen".