21201021022123 has 8 divisors (see below), whose sum is σ = 22122879026688. Its totient is φ = 20279169224424.

The previous prime is 21201021022081. The next prime is 21201021022127. The reversal of 21201021022123 is 32122012010212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21201021022123 - 2⁹ = 21201021021611 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21201021022123.

It is not an unprimeable number, because it can be changed into a prime (21201021022127) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6266440 + ... + 9037162.

It is an arithmetic number, because the mean of its divisors is an integer number (2765359878336).

Almost surely, 2^{21201021022123} is an apocalyptic number.

21201021022123 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21201021022123 is a deficient number, since it is larger than the sum of its proper divisors (921858004565).

21201021022123 is a wasteful number, since it uses less digits than its factorization.

21201021022123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3103433.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 21201021022123 its reverse (32122012010212), we get a palindrome (53323033032335).

The spelling of 21201021022123 in words is "twenty-one trillion, two hundred one billion, twenty-one million, twenty-two thousand, one hundred twenty-three".