1644620000 has 60 divisors (see below), whose sum is σ = 4046061096. Its totient is φ = 657840000.

The previous prime is 1644619987. The next prime is 1644620009. The reversal of 1644620000 is 264461.

It is a happy number.

It is a hoax number, since the sum of its digits (23) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644620009) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 21116 + ... + 61115.

Almost surely, 2^1644620000 is an apocalyptic number.

1644620000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1644620000 is an abundant number, since it is smaller than the sum of its proper divisors (2401441096).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1644620000 is an frugal number, since it uses more digits than its factorization.

1644620000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82261 (or 82238 counting only the distinct ones).

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

The square root of 1644620000 is about 40553.9147308863. The cubic root of 1644620000 is about 1180.3800365486.

Adding to 1644620000 its reverse (264461), we get a palindrome (1644884461).

The spelling of 1644620000 in words is "one billion, six hundred forty-four million, six hundred twenty thousand".