21000021122 has 16 divisors (see below), whose sum is σ = 31603156992. Its totient is φ = 10465667520.

The previous prime is 21000021113. The next prime is 21000021127. The reversal of 21000021122 is 22112000012.

It is a happy number.

It is a super-3 number, since 3×21000021122³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (21000021127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1542698 + ... + 1556250.

It is an arithmetic number, because the mean of its divisors is an integer number (1975197312).

Almost surely, 2^21000021122 is an apocalyptic number.

21000021122 is a deficient number, since it is larger than the sum of its proper divisors (10603135870).

21000021122 is a wasteful number, since it uses less digits than its factorization.

21000021122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16033.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21000021122 its reverse (22112000012), we get a palindrome (43112021134).

The spelling of 21000021122 in words is "twenty-one billion, twenty-one thousand, one hundred twenty-two".