21012101210 has 8 divisors (see below), whose sum is σ = 37821782196. Its totient is φ = 8404840480.

The previous prime is 21012101093. The next prime is 21012101251. The reversal of 21012101210 is 1210121012.

21012101210 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

21012101210 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It can be written as a sum of positive squares in 2 ways, for example, as 18038907481 + 2973193729 = 134309^2 + 54527^2 .

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

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21012101191 and 21012101200.

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, 1050605051 + ... + 1050605070.

Almost surely, 2^21012101210 is an apocalyptic number.

21012101210 is a deficient number, since it is larger than the sum of its proper divisors (16809680986).

21012101210 is a wasteful number, since it uses less digits than its factorization.

21012101210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2101210128.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21012101210 its reverse (1210121012), we get a palindrome (22222222222).

The spelling of 21012101210 in words is "twenty-one billion, twelve million, one hundred one thousand, two hundred ten".