21001212202101 has 32 divisors (see below), whose sum is σ = 29711686567680. Its totient is φ = 13149293454336.

The previous prime is 21001212202099. The next prime is 21001212202109. The reversal of 21001212202101 is 10120221210012.

It is not a de Polignac number, because 21001212202101 - 2¹ = 21001212202099 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001212202109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53632515 + ... + 54022671.

It is an arithmetic number, because the mean of its divisors is an integer number (928490205240).

Almost surely, 2^{21001212202101} is an apocalyptic number.

It is an amenable number.

21001212202101 is a deficient number, since it is larger than the sum of its proper divisors (8710474365579).

21001212202101 is a wasteful number, since it uses less digits than its factorization.

21001212202101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392413.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21001212202101 its reverse (10120221210012), we get a palindrome (31121433412113).

The spelling of 21001212202101 in words is "twenty-one trillion, one billion, two hundred twelve million, two hundred two thousand, one hundred one".