643953135 has 16 divisors (see below), whose sum is σ = 1177514496. Its totient is φ = 294378528.

The previous prime is 643953131. The next prime is 643953137. The reversal of 643953135 is 531359346.

It is not a de Polignac number, because 643953135 - 2² = 643953131 is a prime.

It is a super-3 number, since 3×643953135³ (a number of 27 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 643953093 and 643953102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643953131) 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, 3066339 + ... + 3066548.

It is an arithmetic number, because the mean of its divisors is an integer number (73594656).

Almost surely, 2^643953135 is an apocalyptic number.

643953135 is a deficient number, since it is larger than the sum of its proper divisors (533561361).

643953135 is a wasteful number, since it uses less digits than its factorization.

643953135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6132902.

The product of its digits is 145800, while the sum is 39.

The square root of 643953135 is about 25376.2316942449. The cubic root of 643953135 is about 863.5445626203.

The spelling of 643953135 in words is "six hundred forty-three million, nine hundred fifty-three thousand, one hundred thirty-five".