1643334506121 has 64 divisors (see below), whose sum is σ = 2749820037120. Its totient is φ = 848051466240.

The previous prime is 1643334506087. The next prime is 1643334506137. The reversal of 1643334506121 is 1216054333461.

It is not a de Polignac number, because 1643334506121 - 2¹⁹ = 1643333981833 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1643334506121.

It is not an unprimeable number, because it can be changed into a prime (1643334506141) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 41866921 + ... + 41906153.

It is an arithmetic number, because the mean of its divisors is an integer number (42965938080).

Almost surely, 2^{1643334506121} is an apocalyptic number.

1643334506121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1643334506121 is a deficient number, since it is larger than the sum of its proper divisors (1106485530999).

1643334506121 is a wasteful number, since it uses less digits than its factorization.

1643334506121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40446.

The product of its (nonzero) digits is 155520, while the sum is 39.

Adding to 1643334506121 its reverse (1216054333461), we get a palindrome (2859388839582).

The spelling of 1643334506121 in words is "one trillion, six hundred forty-three billion, three hundred thirty-four million, five hundred six thousand, one hundred twenty-one".