1643107956 has 48 divisors (see below), whose sum is σ = 4453464960. Its totient is φ = 461761920.

The previous prime is 1643107937. The next prime is 1643107969. The reversal of 1643107956 is 6597013461.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 155211 + ... + 165458.

It is an arithmetic number, because the mean of its divisors is an integer number (92780520).

Almost surely, 2^1643107956 is an apocalyptic number.

It is an amenable number.

1643107956 is an abundant number, since it is smaller than the sum of its proper divisors (2810357004).

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

1643107956 is a wasteful number, since it uses less digits than its factorization.

1643107956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320744 (or 320742 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 42.

The square root of 1643107956 is about 40535.2680514142. The cubic root of 1643107956 is about 1180.0181831920.

The spelling of 1643107956 in words is "one billion, six hundred forty-three million, one hundred seven thousand, nine hundred fifty-six".