1644200680 has 16 divisors (see below), whose sum is σ = 3699451620. Its totient is φ = 657680256.

The previous prime is 1644200669. The next prime is 1644200689. The reversal of 1644200680 is 860024461.

1644200680 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 1489496836 + 154703844 = 38594^2 + 12438^2 .

It is a super-3 number, since 3×1644200680³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (1644200689) 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, 20552469 + ... + 20552548.

Almost surely, 2^1644200680 is an apocalyptic number.

1644200680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1644200680 is an abundant number, since it is smaller than the sum of its proper divisors (2055250940).

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

1644200680 is a wasteful number, since it uses less digits than its factorization.

1644200680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41105028 (or 41105024 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 1644200680 is about 40548.7444935105. The cubic root of 1644200680 is about 1180.2797096183.

The spelling of 1644200680 in words is "one billion, six hundred forty-four million, two hundred thousand, six hundred eighty".