20421623344506 has 32 divisors (see below), whose sum is σ = 40908688711488. Its totient is φ = 6796304188800.

The previous prime is 20421623344457. The next prime is 20421623344513. The reversal of 20421623344506 is 60544332612402.

It is a happy number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23706661 + ... + 24552983.

It is an arithmetic number, because the mean of its divisors is an integer number (1278396522234).

Almost surely, 2^{20421623344506} is an apocalyptic number.

20421623344506 is an abundant number, since it is smaller than the sum of its proper divisors (20487065366982).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20421623344506 is a wasteful number, since it uses less digits than its factorization.

20421623344506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852766.

The product of its (nonzero) digits is 829440, while the sum is 42.

Adding to 20421623344506 its reverse (60544332612402), we get a palindrome (80965955956908).

The spelling of 20421623344506 in words is "twenty trillion, four hundred twenty-one billion, six hundred twenty-three million, three hundred forty-four thousand, five hundred six".