643140465 has 32 divisors (see below), whose sum is σ = 1148691456. Its totient is φ = 304570560.

The previous prime is 643140457. The next prime is 643140493. The reversal of 643140465 is 564041346.

643140465 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 643140465 - 2³ = 643140457 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 38229 + ... + 52418.

It is an arithmetic number, because the mean of its divisors is an integer number (35896608).

Almost surely, 2^643140465 is an apocalyptic number.

It is an amenable number.

643140465 is a deficient number, since it is larger than the sum of its proper divisors (505550991).

643140465 is a wasteful number, since it uses less digits than its factorization.

643140465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90709.

The product of its (nonzero) digits is 34560, while the sum is 33.

The square root of 643140465 is about 25360.2142143950. The cubic root of 643140465 is about 863.1811447756.

The spelling of 643140465 in words is "six hundred forty-three million, one hundred forty thousand, four hundred sixty-five".