643654232551 has 8 divisors (see below), whose sum is σ = 704191797504. Its totient is φ = 583453924920.

The previous prime is 643654232503. The next prime is 643654232579. The reversal of 643654232551 is 155232456346.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643654232551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643654202551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84310335 + ... + 84317968.

It is an arithmetic number, because the mean of its divisors is an integer number (88023974688).

Almost surely, 2^643654232551 is an apocalyptic number.

643654232551 is a deficient number, since it is larger than the sum of its proper divisors (60537564953).

643654232551 is a wasteful number, since it uses less digits than its factorization.

643654232551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168628661.

The product of its digits is 2592000, while the sum is 46.

Adding to 643654232551 its reverse (155232456346), we get a palindrome (798886688897).

The spelling of 643654232551 in words is "six hundred forty-three billion, six hundred fifty-four million, two hundred thirty-two thousand, five hundred fifty-one".