21212121212010 has 48 divisors (see below), whose sum is σ = 55157559964416. Its totient is φ = 5655945675744.

The previous prime is 21212121212003. The next prime is 21212121212057. The reversal of 21212121212010 is 1021212121212.

21212121212010 is a `hidden beast` number, since 212 + 121 + 212 + 120 + 1 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12090274 + ... + 13733133.

It is an arithmetic number, because the mean of its divisors is an integer number (1149115832592).

Almost surely, 2^{21212121212010} is an apocalyptic number.

21212121212010 is an abundant number, since it is smaller than the sum of its proper divisors (33945438752406).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21212121212010 is a wasteful number, since it uses less digits than its factorization.

21212121212010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25832547 (or 25832544 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21212121212010 its reverse (1021212121212), we get a palindrome (22233333333222).

The spelling of 21212121212010 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty-one million, two hundred twelve thousand, ten".