643625121 has 4 divisors (see below), whose sum is σ = 858166832. Its totient is φ = 429083412.

The previous prime is 643625119. The next prime is 643625173. The reversal of 643625121 is 121526346.

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 not a de Polignac number, because 643625121 - 2¹ = 643625119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643625621) 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, 107270851 + ... + 107270856.

It is an arithmetic number, because the mean of its divisors is an integer number (214541708).

Almost surely, 2^643625121 is an apocalyptic number.

It is an amenable number.

643625121 is a deficient number, since it is larger than the sum of its proper divisors (214541711).

643625121 is a wasteful number, since it uses less digits than its factorization.

643625121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214541710.

The product of its digits is 8640, while the sum is 30.

The square root of 643625121 is about 25369.7678546730. The cubic root of 643625121 is about 863.3979148812.

The spelling of 643625121 in words is "six hundred forty-three million, six hundred twenty-five thousand, one hundred twenty-one".