643265443521 has 12 divisors (see below), whose sum is σ = 929462618448. Its totient is φ = 428704511064.

The previous prime is 643265443489. The next prime is 643265443559. The reversal of 643265443521 is 125344562346.

643265443521 is a `hidden beast` number, since 6 + 4 + 32 + 6 + 54 + 43 + 521 = 666.

It is not a de Polignac number, because 643265443521 - 2⁵ = 643265443489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643265443621) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11563875 + ... + 11619368.

It is an arithmetic number, because the mean of its divisors is an integer number (77455218204).

Almost surely, 2^643265443521 is an apocalyptic number.

It is an amenable number.

643265443521 is a deficient number, since it is larger than the sum of its proper divisors (286197174927).

643265443521 is a wasteful number, since it uses less digits than its factorization.

643265443521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23186332 (or 23186329 counting only the distinct ones).

The product of its digits is 2073600, while the sum is 45.

The spelling of 643265443521 in words is "six hundred forty-three billion, two hundred sixty-five million, four hundred forty-three thousand, five hundred twenty-one".