643853268949 has 8 divisors (see below), whose sum is σ = 702391963680. Its totient is φ = 585315670800.

The previous prime is 643853268913. The next prime is 643853269009. The reversal of 643853268949 is 949862358346.

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 643853268949 - 2⁹ = 643853268437 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643853260949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1395879 + ... + 1798939.

It is an arithmetic number, because the mean of its divisors is an integer number (87798995460).

Almost surely, 2^643853268949 is an apocalyptic number.

It is an amenable number.

643853268949 is a deficient number, since it is larger than the sum of its proper divisors (58538694731).

643853268949 is a wasteful number, since it uses less digits than its factorization.

643853268949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548291.

The product of its digits is 268738560, while the sum is 67.

The spelling of 643853268949 in words is "six hundred forty-three billion, eight hundred fifty-three million, two hundred sixty-eight thousand, nine hundred forty-nine".