21000000120122 has 4 divisors (see below), whose sum is σ = 31500000180186. Its totient is φ = 10500000060060.

The previous prime is 21000000120067. The next prime is 21000000120137. The reversal of 21000000120122 is 22102100000012.

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., 12577867947841 + 8422132172281 = 3546529^2 + 2902091^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5250000030029 + ... + 5250000030032.

Almost surely, 2^{21000000120122} is an apocalyptic number.

21000000120122 is a deficient number, since it is larger than the sum of its proper divisors (10500000060064).

21000000120122 is a wasteful number, since it uses less digits than its factorization.

21000000120122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10500000060063.

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

Adding to 21000000120122 its reverse (22102100000012), we get a palindrome (43102100120134).

The spelling of 21000000120122 in words is "twenty-one trillion, one hundred twenty thousand, one hundred twenty-two".