21020212101 has 32 divisors (see below), whose sum is σ = 32774688000. Its totient is φ = 11735239680.

The previous prime is 21020212099. The next prime is 21020212111. The reversal of 21020212101 is 10121202012.

It is not a de Polignac number, because 21020212101 - 2¹ = 21020212099 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020212111) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 135805 + ... + 245933.

It is an arithmetic number, because the mean of its divisors is an integer number (1024209000).

Almost surely, 2^21020212101 is an apocalyptic number.

21020212101 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21020212101 is a deficient number, since it is larger than the sum of its proper divisors (11754475899).

21020212101 is a wasteful number, since it uses less digits than its factorization.

21020212101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110349.

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

Adding to 21020212101 its reverse (10121202012), we get a palindrome (31141414113).

The spelling of 21020212101 in words is "twenty-one billion, twenty million, two hundred twelve thousand, one hundred one".