21020120122 has 8 divisors (see below), whose sum is σ = 31581284436. Its totient is φ = 10493025312.

The previous prime is 21020120111. The next prime is 21020120131. The reversal of 21020120122 is 22102102012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 13598125321 + 7421994801 = 116611^2 + 86151^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8515833 + ... + 8518300.

Almost surely, 2^21020120122 is an apocalyptic number.

21020120122 is a deficient number, since it is larger than the sum of its proper divisors (10561164314).

21020120122 is a wasteful number, since it uses less digits than its factorization.

21020120122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17034752.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21020120122 its reverse (22102102012), we get a palindrome (43122222134).

The spelling of 21020120122 in words is "twenty-one billion, twenty million, one hundred twenty thousand, one hundred twenty-two".