6465643920 has 60 divisors (see below), whose sum is σ = 21713789916. Its totient is φ = 1724171520.

The previous prime is 6465643913. The next prime is 6465643939. The reversal of 6465643920 is 293465646.

6465643920 is a `hidden beast` number, since 64 + 6 + 564 + 3 + 9 + 20 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1329915024 + 5135728896 = 36468^2 + 71664^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (45).

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 11 ways as a sum of consecutive naturals, for example, 4489311 + ... + 4490750.

Almost surely, 2^6465643920 is an apocalyptic number.

6465643920 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6465643920 is an abundant number, since it is smaller than the sum of its proper divisors (15248145996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6465643920 is a wasteful number, since it uses less digits than its factorization.

6465643920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8980080 (or 8980071 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 45.

The square root of 6465643920 is about 80409.2278286516. The cubic root of 6465643920 is about 1862.9617053938.

The spelling of 6465643920 in words is "six billion, four hundred sixty-five million, six hundred forty-three thousand, nine hundred twenty".