21794764536121 has 4 divisors (see below), whose sum is σ = 23076809508852. Its totient is φ = 20512719563392.

The previous prime is 21794764536107. The next prime is 21794764536169. The reversal of 21794764536121 is 12163546749712.

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 8783132413225 + 13011632122896 = 2963635^2 + 3607164^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21794764536121 is a prime.

It is a super-2 number, since 2×21794764536121² (a number of 27 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21794764576121) 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, 641022486340 + ... + 641022486373.

It is an arithmetic number, because the mean of its divisors is an integer number (5769202377213).

Almost surely, 2^{21794764536121} is an apocalyptic number.

It is an amenable number.

21794764536121 is a deficient number, since it is larger than the sum of its proper divisors (1282044972731).

21794764536121 is a wasteful number, since it uses less digits than its factorization.

21794764536121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1282044972730.

The product of its digits is 15240960, while the sum is 58.

The spelling of 21794764536121 in words is "twenty-one trillion, seven hundred ninety-four billion, seven hundred sixty-four million, five hundred thirty-six thousand, one hundred twenty-one".