643464953 has 4 divisors (see below), whose sum is σ = 643593060. Its totient is φ = 643336848.

The previous prime is 643464949. The next prime is 643464959. The reversal of 643464953 is 359464346.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 558235129 + 85229824 = 23627^2 + 9232^2 .

It is a cyclic number.

It is not a de Polignac number, because 643464953 - 2² = 643464949 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643464959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56198 + ... + 66671.

It is an arithmetic number, because the mean of its divisors is an integer number (160898265).

Almost surely, 2^643464953 is an apocalyptic number.

It is an amenable number.

643464953 is a deficient number, since it is larger than the sum of its proper divisors (128107).

643464953 is a wasteful number, since it uses less digits than its factorization.

643464953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128106.

The product of its digits is 933120, while the sum is 44.

The square root of 643464953 is about 25366.6109876743. The cubic root of 643464953 is about 863.3262892379.

The spelling of 643464953 in words is "six hundred forty-three million, four hundred sixty-four thousand, nine hundred fifty-three".