643545515 has 8 divisors (see below), whose sum is σ = 772987488. Its totient is φ = 514347840.

The previous prime is 643545499. The next prime is 643545517. The reversal of 643545515 is 515545346.

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

It is not a de Polignac number, because 643545515 - 2⁴ = 643545499 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643545517) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55226 + ... + 65855.

It is an arithmetic number, because the mean of its divisors is an integer number (96623436).

Almost surely, 2^643545515 is an apocalyptic number.

643545515 is a deficient number, since it is larger than the sum of its proper divisors (129441973).

643545515 is a wasteful number, since it uses less digits than its factorization.

643545515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122149.

The product of its digits is 180000, while the sum is 38.

The square root of 643545515 is about 25368.1988915256. The cubic root of 643545515 is about 863.3623173022.

The spelling of 643545515 in words is "six hundred forty-three million, five hundred forty-five thousand, five hundred fifteen".