21222212121201 has 128 divisors (see below), whose sum is σ = 36851869551616. Its totient is φ = 10566262702080.

The previous prime is 21222212121197. The next prime is 21222212121223. The reversal of 21222212121201 is 10212121222212.

It is not a de Polignac number, because 21222212121201 - 2² = 21222212121197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21222212125201) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 44743845 + ... + 45215661.

It is an arithmetic number, because the mean of its divisors is an integer number (287905230872).

Almost surely, 2^{21222212121201} is an apocalyptic number.

21222212121201 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21222212121201 is a deficient number, since it is larger than the sum of its proper divisors (15629657430415).

21222212121201 is a wasteful number, since it uses less digits than its factorization.

21222212121201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472011.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21222212121201 its reverse (10212121222212), we get a palindrome (31434333343413).

The spelling of 21222212121201 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred twelve million, one hundred twenty-one thousand, two hundred one".