1644530563 has 16 divisors (see below), whose sum is σ = 1830443776. Its totient is φ = 1467227520.

The previous prime is 1644530551. The next prime is 1644530599. The reversal of 1644530563 is 3650354461.

It is not a de Polignac number, because 1644530563 - 2²⁵ = 1610976131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1644530963) 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, 399745 + ... + 403837.

It is an arithmetic number, because the mean of its divisors is an integer number (114402736).

Almost surely, 2^1644530563 is an apocalyptic number.

1644530563 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1644530563 is a deficient number, since it is larger than the sum of its proper divisors (185913213).

1644530563 is a wasteful number, since it uses less digits than its factorization.

1644530563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5134.

The product of its (nonzero) digits is 129600, while the sum is 37.

The square root of 1644530563 is about 40552.8120233357. The cubic root of 1644530563 is about 1180.3586391917.

The spelling of 1644530563 in words is "one billion, six hundred forty-four million, five hundred thirty thousand, five hundred sixty-three".