643242262065 has 16 divisors (see below), whose sum is σ = 1108355898048. Its totient is φ = 316673113536.

The previous prime is 643242262063. The next prime is 643242262073. The reversal of 643242262065 is 560262242346.

It is a happy number.

It is not a de Polignac number, because 643242262065 - 2¹ = 643242262063 is a prime.

It is not an unprimeable number, because it can be changed into a prime (643242262063) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1649338939 + ... + 1649339328.

It is an arithmetic number, because the mean of its divisors is an integer number (69272243628).

Almost surely, 2^643242262065 is an apocalyptic number.

643242262065 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

643242262065 is a deficient number, since it is larger than the sum of its proper divisors (465113635983).

643242262065 is a wasteful number, since it uses less digits than its factorization.

643242262065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3298678288.

The product of its (nonzero) digits is 829440, while the sum is 42.

The spelling of 643242262065 in words is "six hundred forty-three billion, two hundred forty-two million, two hundred sixty-two thousand, sixty-five".