21021021210 has 64 divisors (see below), whose sum is σ = 57723611904. Its totient is φ = 4799308800.

The previous prime is 21021021199. The next prime is 21021021269. The reversal of 21021021210 is 1212012012.

It is a super-2 number, since 2×21021021210² (a number of 21 digits) contains 22 as substring.

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 31 ways as a sum of consecutive naturals, for example, 128200 + ... + 241820.

It is an arithmetic number, because the mean of its divisors is an integer number (901931436).

Almost surely, 2^21021021210 is an apocalyptic number.

21021021210 is an abundant number, since it is smaller than the sum of its proper divisors (36702590694).

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

21021021210 is a wasteful number, since it uses less digits than its factorization.

21021021210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114519.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21021021210 its reverse (1212012012), we get a palindrome (22233033222).

The spelling of 21021021210 in words is "twenty-one billion, twenty-one million, twenty-one thousand, two hundred ten".