20402131041221 has 4 divisors (see below), whose sum is σ = 20468587494432. Its totient is φ = 20335674588012.

The previous prime is 20402131041211. The next prime is 20402131041241. The reversal of 20402131041221 is 12214013120402.

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 not a de Polignac number, because 20402131041221 - 2⁶ = 20402131041157 is a prime.

It is a super-3 number, since 3×20402131041221³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20402131041211) 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, 33228226145 + ... + 33228226758.

It is an arithmetic number, because the mean of its divisors is an integer number (5117146873608).

Almost surely, 2^{20402131041221} is an apocalyptic number.

It is an amenable number.

20402131041221 is a deficient number, since it is larger than the sum of its proper divisors (66456453211).

20402131041221 is an equidigital number, since it uses as much as digits as its factorization.

20402131041221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66456453210.

The product of its (nonzero) digits is 768, while the sum is 23.

Adding to 20402131041221 its reverse (12214013120402), we get a palindrome (32616144161623).

The spelling of 20402131041221 in words is "twenty trillion, four hundred two billion, one hundred thirty-one million, forty-one thousand, two hundred twenty-one".