21212122010 has 16 divisors (see below), whose sum is σ = 38559859272. Its totient is φ = 8400840000.

The previous prime is 21212121971. The next prime is 21212122027. The reversal of 21212122010 is 1022121212.

It can be written as a sum of positive squares in 4 ways, for example, as 15249039169 + 5963082841 = 123487^2 + 77221^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10500041 + ... + 10502060.

Almost surely, 2^21212122010 is an apocalyptic number.

21212122010 is a deficient number, since it is larger than the sum of its proper divisors (17347737262).

21212122010 is a wasteful number, since it uses less digits than its factorization.

21212122010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21002209.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21212122010 its reverse (1022121212), we get a palindrome (22234243222).

The spelling of 21212122010 in words is "twenty-one billion, two hundred twelve million, one hundred twenty-two thousand, ten".