6436641121 has 4 divisors (see below), whose sum is σ = 6438300100. Its totient is φ = 6434982144.

The previous prime is 6436641091. The next prime is 6436641173. The reversal of 6436641121 is 1211466346.

6436641121 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1211466346 = 2 ⋅605733173.

It can be written as a sum of positive squares in 2 ways, for example, as 3185360721 + 3251280400 = 56439^2 + 57020^2 .

It is a cyclic number.

It is not a de Polignac number, because 6436641121 - 2⁷ = 6436640993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6436644121) 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, 823656 + ... + 831433.

It is an arithmetic number, because the mean of its divisors is an integer number (1609575025).

Almost surely, 2^6436641121 is an apocalyptic number.

It is an amenable number.

6436641121 is a deficient number, since it is larger than the sum of its proper divisors (1658979).

6436641121 is a wasteful number, since it uses less digits than its factorization.

6436641121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1658978.

The product of its digits is 20736, while the sum is 34.

The square root of 6436641121 is about 80228.6801648887. The cubic root of 6436641121 is about 1860.1719809566.

The spelling of 6436641121 in words is "six billion, four hundred thirty-six million, six hundred forty-one thousand, one hundred twenty-one".