643242505 has 8 divisors (see below), whose sum is σ = 772034112. Its totient is φ = 514498608.

The previous prime is 643242371. The next prime is 643242527. The reversal of 643242505 is 505242346.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 643242505 - 2¹⁵ = 643209737 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33412 + ... + 49018.

It is an arithmetic number, because the mean of its divisors is an integer number (96504264).

Almost surely, 2^643242505 is an apocalyptic number.

It is an amenable number.

643242505 is a deficient number, since it is larger than the sum of its proper divisors (128791607).

643242505 is a wasteful number, since it uses less digits than its factorization.

643242505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23855.

The product of its (nonzero) digits is 28800, while the sum is 31.

The square root of 643242505 is about 25362.2259472626. The cubic root of 643242505 is about 863.2267928369.

The spelling of 643242505 in words is "six hundred forty-three million, two hundred forty-two thousand, five hundred five".