1643630099 has 4 divisors (see below), whose sum is σ = 1683718680. Its totient is φ = 1603541520.

The previous prime is 1643630069. The next prime is 1643630111. The reversal of 1643630099 is 9900363461.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1643630099 - 2⁸ = 1643629843 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 40088539 = 1643630099 / (1 + 6 + 4 + 3 + 6 + 3 + 0 + 0 + 9 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643630029) 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, 20044229 + ... + 20044310.

It is an arithmetic number, because the mean of its divisors is an integer number (420929670).

Almost surely, 2^1643630099 is an apocalyptic number.

1643630099 is a deficient number, since it is larger than the sum of its proper divisors (40088581).

1643630099 is an equidigital number, since it uses as much as digits as its factorization.

1643630099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40088580.

The product of its (nonzero) digits is 104976, while the sum is 41.

The square root of 1643630099 is about 40541.7081411230. The cubic root of 1643630099 is about 1180.1431644262.

The spelling of 1643630099 in words is "one billion, six hundred forty-three million, six hundred thirty thousand, ninety-nine".