21022200165506 has 32 divisors (see below), whose sum is σ = 32298646702080. Its totient is φ = 10256473949904.

The previous prime is 21022200165497. The next prime is 21022200165511. The reversal of 21022200165506 is 60556100222012.

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, 457548371 + ... + 457594313.

It is an arithmetic number, because the mean of its divisors is an integer number (1009332709440).

Almost surely, 2^{21022200165506} is an apocalyptic number.

21022200165506 is a deficient number, since it is larger than the sum of its proper divisors (11276446536574).

21022200165506 is a wasteful number, since it uses less digits than its factorization.

21022200165506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51150.

The product of its (nonzero) digits is 14400, while the sum is 32.

Adding to 21022200165506 its reverse (60556100222012), we get a palindrome (81578300387518).

The spelling of 21022200165506 in words is "twenty-one trillion, twenty-two billion, two hundred million, one hundred sixty-five thousand, five hundred six".