20121001200221 has 4 divisors (see below), whose sum is σ = 20122176715452. Its totient is φ = 20119825684992.

The previous prime is 20121001200217. The next prime is 20121001200229. The reversal of 20121001200221 is 12200210012102.

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 8519218312900 + 11601782887321 = 2918770^2 + 3406139^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121001200221 - 2² = 20121001200217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20121001200196 and 20121001200205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121001200229) 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, 587731940 + ... + 587766173.

It is an arithmetic number, because the mean of its divisors is an integer number (5030544178863).

Almost surely, 2^{20121001200221} is an apocalyptic number.

It is an amenable number.

20121001200221 is a deficient number, since it is larger than the sum of its proper divisors (1175515231).

20121001200221 is a wasteful number, since it uses less digits than its factorization.

20121001200221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1175515230.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20121001200221 its reverse (12200210012102), we get a palindrome (32321211212323).

The spelling of 20121001200221 in words is "twenty trillion, one hundred twenty-one billion, one million, two hundred thousand, two hundred twenty-one".