643105523741 has 4 divisors (see below), whose sum is σ = 649735477692. Its totient is φ = 636475569792.

The previous prime is 643105523737. The next prime is 643105523783. The reversal of 643105523741 is 147325501346.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 375217502500 + 267888021241 = 612550^2 + 517579^2 .

It is a cyclic number.

It is not a de Polignac number, because 643105523741 - 2² = 643105523737 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 (643105526741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3314976830 + ... + 3314977023.

It is an arithmetic number, because the mean of its divisors is an integer number (162433869423).

Almost surely, 2^643105523741 is an apocalyptic number.

It is an amenable number.

643105523741 is a deficient number, since it is larger than the sum of its proper divisors (6629953951).

643105523741 is an equidigital number, since it uses as much as digits as its factorization.

643105523741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6629953950.

The product of its (nonzero) digits is 302400, while the sum is 41.

The spelling of 643105523741 in words is "six hundred forty-three billion, one hundred five million, five hundred twenty-three thousand, seven hundred forty-one".