643618453 has 16 divisors (see below), whose sum is σ = 727664256. Its totient is φ = 565931520.

The previous prime is 643618447. The next prime is 643618529. The reversal of 643618453 is 354816346.

It is a cyclic number.

It is not a de Polignac number, because 643618453 - 2²⁹ = 106747541 is a prime.

It is a super-2 number, since 2×643618453² = 828489426084226418, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643618253) 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, 2328 + ... + 35953.

It is an arithmetic number, because the mean of its divisors is an integer number (45479016).

Almost surely, 2^643618453 is an apocalyptic number.

It is an amenable number.

643618453 is a deficient number, since it is larger than the sum of its proper divisors (84045803).

643618453 is a wasteful number, since it uses less digits than its factorization.

643618453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38364.

The product of its digits is 207360, while the sum is 40.

The square root of 643618453 is about 25369.6364380730. The cubic root of 643618453 is about 863.3949332505.

The spelling of 643618453 in words is "six hundred forty-three million, six hundred eighteen thousand, four hundred fifty-three".