643363654553 has 4 divisors (see below), whose sum is σ = 645432348288. Its totient is φ = 641294960820.

The previous prime is 643363654547. The next prime is 643363654621. The reversal of 643363654553 is 355456363346.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 643363654553 - 2⁴ = 643363654537 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 643363654495 and 643363654504.

It is not an unprimeable number, because it can be changed into a prime (643363654513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1034346401 + ... + 1034347022.

It is an arithmetic number, because the mean of its divisors is an integer number (161358087072).

Almost surely, 2^643363654553 is an apocalyptic number.

It is an amenable number.

643363654553 is a deficient number, since it is larger than the sum of its proper divisors (2068693735).

643363654553 is a wasteful number, since it uses less digits than its factorization.

643363654553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2068693734.

The product of its digits is 34992000, while the sum is 53.

The spelling of 643363654553 in words is "six hundred forty-three billion, three hundred sixty-three million, six hundred fifty-four thousand, five hundred fifty-three".