21201021021111 has 16 divisors (see below), whose sum is σ = 29498087533824. Its totient is φ = 13519026545024.

The previous prime is 21201021021091. The next prime is 21201021021161. The reversal of 21201021021111 is 11112012010212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21201021021111 - 2¹¹ = 21201021019063 is a prime.

It is a super-3 number, since 3×21201021021111³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201021021161) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3259746 + ... + 7282031.

It is an arithmetic number, because the mean of its divisors is an integer number (1843630470864).

Almost surely, 2^{21201021021111} is an apocalyptic number.

21201021021111 is a deficient number, since it is larger than the sum of its proper divisors (8297066512713).

21201021021111 is a wasteful number, since it uses less digits than its factorization.

21201021021111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10570950.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21201021021111 its reverse (11112012010212), we get a palindrome (32313033031323).

The spelling of 21201021021111 in words is "twenty-one trillion, two hundred one billion, twenty-one million, twenty-one thousand, one hundred eleven".