643446234621 has 16 divisors (see below), whose sum is σ = 954176523520. Its totient is φ = 428548877280.

The previous prime is 643446234583. The next prime is 643446234647. The reversal of 643446234621 is 126432644346.

It is not a de Polignac number, because 643446234621 - 2²³ = 643437846013 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643446234671) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11507125 + ... + 11562906.

It is an arithmetic number, because the mean of its divisors is an integer number (59636032720).

Almost surely, 2^643446234621 is an apocalyptic number.

It is an amenable number.

643446234621 is a deficient number, since it is larger than the sum of its proper divisors (310730288899).

643446234621 is a wasteful number, since it uses less digits than its factorization.

643446234621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23071073 (or 23071067 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 45.

Adding to 643446234621 its reverse (126432644346), we get a palindrome (769878878967).

The spelling of 643446234621 in words is "six hundred forty-three billion, four hundred forty-six million, two hundred thirty-four thousand, six hundred twenty-one".