20421120506445 has 160 divisors (see below), whose sum is σ = 37205869345920. Its totient is φ = 10714547289600.

The previous prime is 20421120506441. The next prime is 20421120506471. The reversal of 20421120506445 is 54460502112402.

20421120506445 is a `hidden beast` number, since 2 + 0 + 4 + 2 + 1 + 1 + 2 + 0 + 5 + 0 + 644 + 5 = 666.

It is not a de Polignac number, because 20421120506445 - 2² = 20421120506441 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20421120506441) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 9371784366 + ... + 9371786544.

It is an arithmetic number, because the mean of its divisors is an integer number (232536683412).

Almost surely, 2^{20421120506445} is an apocalyptic number.

It is an amenable number.

20421120506445 is a deficient number, since it is larger than the sum of its proper divisors (16784748839475).

20421120506445 is a wasteful number, since it uses less digits than its factorization.

20421120506445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3657 (or 3648 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

Adding to 20421120506445 its reverse (54460502112402), we get a palindrome (74881622618847).

The spelling of 20421120506445 in words is "twenty trillion, four hundred twenty-one billion, one hundred twenty million, five hundred six thousand, four hundred forty-five".