2121638537069 has 4 divisors (see below), whose sum is σ = 2122238042880. Its totient is φ = 2121039031260.

The previous prime is 2121638536981. The next prime is 2121638537093. The reversal of 2121638537069 is 9607358361212.

It is a happy number.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2121638537069 is a prime.

It is a super-2 number, since 2×2121638537069² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

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 2121638537069.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121638507069) 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, 299747597 + ... + 299754674.

It is an arithmetic number, because the mean of its divisors is an integer number (530559510720).

Almost surely, 2^{2121638537069} is an apocalyptic number.

It is an amenable number.

2121638537069 is a deficient number, since it is larger than the sum of its proper divisors (599505811).

2121638537069 is an equidigital number, since it uses as much as digits as its factorization.

2121638537069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 599505810.

The product of its (nonzero) digits is 3265920, while the sum is 53.

The spelling of 2121638537069 in words is "two trillion, one hundred twenty-one billion, six hundred thirty-eight million, five hundred thirty-seven thousand, sixty-nine".