21012000122 has 4 divisors (see below), whose sum is σ = 31518000186. Its totient is φ = 10506000060.

The previous prime is 21012000109. The next prime is 21012000133. The reversal of 21012000122 is 22100021012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 17854571641 + 3157428481 = 133621^2 + 56191^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5253000029 + ... + 5253000032.

Almost surely, 2^21012000122 is an apocalyptic number.

21012000122 is a deficient number, since it is larger than the sum of its proper divisors (10506000064).

21012000122 is a wasteful number, since it uses less digits than its factorization.

21012000122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10506000063.

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

Adding to 21012000122 its reverse (22100021012), we get a palindrome (43112021134).

The spelling of 21012000122 in words is "twenty-one billion, twelve million, one hundred twenty-two", and thus it is an aban number.