643252555 has 16 divisors (see below), whose sum is σ = 845093088. Its totient is φ = 466144000.

The previous prime is 643252541. The next prime is 643252583. The reversal of 643252555 is 555252346.

It is a de Polignac number, because none of the positive numbers 2^k-643252555 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5356 + ... + 36265.

It is an arithmetic number, because the mean of its divisors is an integer number (52818318).

Almost surely, 2^643252555 is an apocalyptic number.

643252555 is a deficient number, since it is larger than the sum of its proper divisors (201840533).

643252555 is a wasteful number, since it uses less digits than its factorization.

643252555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41918.

The product of its digits is 180000, while the sum is 37.

The square root of 643252555 is about 25362.4240757858. The cubic root of 643252555 is about 863.2312884893.

The spelling of 643252555 in words is "six hundred forty-three million, two hundred fifty-two thousand, five hundred fifty-five".