643614521 has 8 divisors (see below), whose sum is σ = 709077888. Its totient is φ = 579310000.

The previous prime is 643614479. The next prime is 643614541. The reversal of 643614521 is 125416346.

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 643614521 - 2¹⁰ = 643613497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643614541) 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, 288545 + ... + 290766.

It is an arithmetic number, because the mean of its divisors is an integer number (88634736).

Almost surely, 2^643614521 is an apocalyptic number.

It is an amenable number.

643614521 is a deficient number, since it is larger than the sum of its proper divisors (65463367).

643614521 is a wasteful number, since it uses less digits than its factorization.

643614521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579423.

The product of its digits is 17280, while the sum is 32.

The square root of 643614521 is about 25369.5589437420. The cubic root of 643614521 is about 863.3931750268.

The spelling of 643614521 in words is "six hundred forty-three million, six hundred fourteen thousand, five hundred twenty-one".