643406757241 has 16 divisors (see below), whose sum is σ = 684363588160. Its totient is φ = 603161303040.

The previous prime is 643406757193. The next prime is 643406757247. The reversal of 643406757241 is 142757604346.

It is a cyclic number.

It is not a de Polignac number, because 643406757241 - 2²¹ = 643404660089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643406757247) 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, 12925921 + ... + 12975601.

It is an arithmetic number, because the mean of its divisors is an integer number (42772724260).

Almost surely, 2^643406757241 is an apocalyptic number.

It is an amenable number.

643406757241 is a deficient number, since it is larger than the sum of its proper divisors (40956830919).

643406757241 is a wasteful number, since it uses less digits than its factorization.

643406757241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56824.

The product of its (nonzero) digits is 3386880, while the sum is 49.

The spelling of 643406757241 in words is "six hundred forty-three billion, four hundred six million, seven hundred fifty-seven thousand, two hundred forty-one".