643958418435 has 32 divisors (see below), whose sum is σ = 1049639040000. Its totient is φ = 337029770496.

The previous prime is 643958418431. The next prime is 643958418437. The reversal of 643958418435 is 534814859346.

It is a happy number.

It is not a de Polignac number, because 643958418435 - 2² = 643958418431 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643958418431) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 135835 + ... + 1142964.

It is an arithmetic number, because the mean of its divisors is an integer number (32801220000).

Almost surely, 2^643958418435 is an apocalyptic number.

643958418435 is a deficient number, since it is larger than the sum of its proper divisors (405680621565).

643958418435 is a wasteful number, since it uses less digits than its factorization.

643958418435 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1279435.

The product of its digits is 49766400, while the sum is 60.

The spelling of 643958418435 in words is "six hundred forty-three billion, nine hundred fifty-eight million, four hundred eighteen thousand, four hundred thirty-five".