21020210121009 has 64 divisors (see below), whose sum is σ = 31287886350336. Its totient is φ = 12445749120000.

The previous prime is 21020210120989. The next prime is 21020210121019. The reversal of 21020210121009 is 90012101202012.

It is not a de Polignac number, because 21020210121009 - 2²⁰ = 21020209072433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21020210121019) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1392889554 + ... + 1392904644.

It is an arithmetic number, because the mean of its divisors is an integer number (488873224224).

Almost surely, 2^{21020210121009} is an apocalyptic number.

It is an amenable number.

21020210121009 is a deficient number, since it is larger than the sum of its proper divisors (10267676229327).

21020210121009 is a wasteful number, since it uses less digits than its factorization.

21020210121009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20550.

The product of its (nonzero) digits is 144, while the sum is 21.

The spelling of 21020210121009 in words is "twenty-one trillion, twenty billion, two hundred ten million, one hundred twenty-one thousand, nine".