20421312204345 has 16 divisors (see below), whose sum is σ = 35187491798592. Its totient is φ = 10053569085120.

The previous prime is 20421312204341. The next prime is 20421312204347. The reversal of 20421312204345 is 54340221312402.

It is a happy number.

It is not a de Polignac number, because 20421312204345 - 2² = 20421312204341 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20421312204341) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52362338791 + ... + 52362339180.

It is an arithmetic number, because the mean of its divisors is an integer number (2199218237412).

Almost surely, 2^{20421312204345} is an apocalyptic number.

It is an amenable number.

20421312204345 is a deficient number, since it is larger than the sum of its proper divisors (14766179594247).

20421312204345 is a wasteful number, since it uses less digits than its factorization.

20421312204345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104724677992.

The product of its (nonzero) digits is 46080, while the sum is 33.

Adding to 20421312204345 its reverse (54340221312402), we get a palindrome (74761533516747).

The spelling of 20421312204345 in words is "twenty trillion, four hundred twenty-one billion, three hundred twelve million, two hundred four thousand, three hundred forty-five".