1643063957 has 8 divisors (see below), whose sum is σ = 1755112536. Its totient is φ = 1532726272.

The previous prime is 1643063941. The next prime is 1643063959. The reversal of 1643063957 is 7593603461.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 20666116 + 1622397841 = 4546^2 + 40279^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1643063957 - 2⁴ = 1643063941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643063959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 425738 + ... + 429579.

It is an arithmetic number, because the mean of its divisors is an integer number (219389067).

Almost surely, 2^1643063957 is an apocalyptic number.

1643063957 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

1643063957 is a deficient number, since it is larger than the sum of its proper divisors (112048579).

1643063957 is a wasteful number, since it uses less digits than its factorization.

1643063957 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 855447.

The product of its (nonzero) digits is 408240, while the sum is 44.

The square root of 1643063957 is about 40534.7253228636. The cubic root of 1643063957 is about 1180.0076502903.

The spelling of 1643063957 in words is "one billion, six hundred forty-three million, sixty-three thousand, nine hundred fifty-seven".