2121644654105 has 4 divisors (see below), whose sum is σ = 2545973584932. Its totient is φ = 1697315723280.

The previous prime is 2121644654039. The next prime is 2121644654113. The reversal of 2121644654105 is 5014564461212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1263153457801 + 858491196304 = 1123901^2 + 926548^2 .

It is a de Polignac number, because none of the positive numbers 2^k-2121644654105 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 212164465406 + ... + 212164465415.

It is an arithmetic number, because the mean of its divisors is an integer number (636493396233).

Almost surely, 2^{2121644654105} is an apocalyptic number.

It is an amenable number.

2121644654105 is a deficient number, since it is larger than the sum of its proper divisors (424328930827).

2121644654105 is an equidigital number, since it uses as much as digits as its factorization.

2121644654105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424328930826.

The product of its (nonzero) digits is 230400, while the sum is 41.

The spelling of 2121644654105 in words is "two trillion, one hundred twenty-one billion, six hundred forty-four million, six hundred fifty-four thousand, one hundred five".