20351475810121 has 3 divisors (see below), whose sum is σ = 20351480321383. Its totient is φ = 20351471298860.

The previous prime is 20351475810109. The next prime is 20351475810131. The reversal of 20351475810121 is 12101857415302.

The square root of 20351475810121 is 4511261.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1209975800121 + 19141500010000 = 1099989^2 + 4375100^2 .

It is not a de Polignac number, because 20351475810121 - 2¹⁷ = 20351475679049 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20351475810131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 2255631 + ... + 6766891.

Almost surely, 2^{20351475810121} is an apocalyptic number.

20351475810121 is the 4511261-st square number.

20351475810121 is the 2255631-st centered octagonal number.

It is an amenable number.

20351475810121 is a deficient number, since it is larger than the sum of its proper divisors (4511262).

20351475810121 is an frugal number, since it uses more digits than its factorization.

20351475810121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9022522 (or 4511261 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 40.

The spelling of 20351475810121 in words is "twenty trillion, three hundred fifty-one billion, four hundred seventy-five million, eight hundred ten thousand, one hundred twenty-one".