643412121 has 8 divisors (see below), whose sum is σ = 935872224. Its totient is φ = 389946720.

The previous prime is 643412101. The next prime is 643412137. The reversal of 643412121 is 121214346.

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

It is not a de Polignac number, because 643412121 - 2¹⁵ = 643379353 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643412091 and 643412100.

It is not an unprimeable number, because it can be changed into a prime (643412101) 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, 9748636 + ... + 9748701.

It is an arithmetic number, because the mean of its divisors is an integer number (116984028).

Almost surely, 2^643412121 is an apocalyptic number.

It is an amenable number.

643412121 is a deficient number, since it is larger than the sum of its proper divisors (292460103).

643412121 is a wasteful number, since it uses less digits than its factorization.

643412121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19497351.

The product of its digits is 1152, while the sum is 24.

The square root of 643412121 is about 25365.5695973893. The cubic root of 643412121 is about 863.3026606509.

Adding to 643412121 its reverse (121214346), we get a palindrome (764626467).

The spelling of 643412121 in words is "six hundred forty-three million, four hundred twelve thousand, one hundred twenty-one".