643332056551 has 8 divisors (see below), whose sum is σ = 674889386400. Its totient is φ = 612399624480.

The previous prime is 643332056399. The next prime is 643332056569. The reversal of 643332056551 is 155650233346.

643332056551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 643332056551 - 2²¹ = 643329959399 is a prime.

It is a super-2 number, since 2×643332056551² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 643332056498 and 643332056507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643332056351) 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, 156222336 + ... + 156226453.

It is an arithmetic number, because the mean of its divisors is an integer number (84361173300).

Almost surely, 2^643332056551 is an apocalyptic number.

643332056551 is a deficient number, since it is larger than the sum of its proper divisors (31557329849).

643332056551 is a wasteful number, since it uses less digits than its factorization.

643332056551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312448889.

The product of its (nonzero) digits is 972000, while the sum is 43.

Adding to 643332056551 its reverse (155650233346), we get a palindrome (798982289897).

The spelling of 643332056551 in words is "six hundred forty-three billion, three hundred thirty-two million, fifty-six thousand, five hundred fifty-one".