21605012022 has 32 divisors (see below), whose sum is σ = 47841773184. Its totient is φ = 6449256000.

The previous prime is 21605012021. The next prime is 21605012041. The reversal of 21605012022 is 22021050612.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21605012022.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21605012021) 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, 2438479 + ... + 2447322.

It is an arithmetic number, because the mean of its divisors is an integer number (1495055412).

Almost surely, 2^21605012022 is an apocalyptic number.

21605012022 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21605012022 is an abundant number, since it is smaller than the sum of its proper divisors (26236761162).

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

21605012022 is a wasteful number, since it uses less digits than its factorization.

21605012022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4885884.

The product of its (nonzero) digits is 480, while the sum is 21.

Adding to 21605012022 its reverse (22021050612), we get a palindrome (43626062634).

The spelling of 21605012022 in words is "twenty-one billion, six hundred five million, twelve thousand, twenty-two".