643420123245 has 16 divisors (see below), whose sum is σ = 1143857997120. Its totient is φ = 343157398992.

The previous prime is 643420123219. The next prime is 643420123267. The reversal of 643420123245 is 542321024346.

643420123245 is a `hidden beast` number, since 64 + 342 + 0 + 12 + 3 + 245 = 666.

It is not a de Polignac number, because 643420123245 - 2¹⁸ = 643419861101 is a prime.

It is a super-2 number, since 2×643420123245² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2383037359 + ... + 2383037628.

It is an arithmetic number, because the mean of its divisors is an integer number (71491124820).

Almost surely, 2^643420123245 is an apocalyptic number.

It is an amenable number.

643420123245 is a deficient number, since it is larger than the sum of its proper divisors (500437873875).

643420123245 is a wasteful number, since it uses less digits than its factorization.

643420123245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4766075001 (or 4766074995 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 36.

The spelling of 643420123245 in words is "six hundred forty-three billion, four hundred twenty million, one hundred twenty-three thousand, two hundred forty-five".