21221000111001 has 32 divisors (see below), whose sum is σ = 29255793573888. Its totient is φ = 13673541087360.

The previous prime is 21221000110969. The next prime is 21221000111081. The reversal of 21221000111001 is 10011100012212.

It is not a de Polignac number, because 21221000111001 - 2⁵ = 21221000110969 is a prime.

It is a super-2 number, since 2×21221000111001² (a number of 27 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21221000111081) 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, 9674640 + ... + 11663646.

It is an arithmetic number, because the mean of its divisors is an integer number (914243549184).

Almost surely, 2^{21221000111001} is an apocalyptic number.

It is an amenable number.

21221000111001 is a deficient number, since it is larger than the sum of its proper divisors (8034793462887).

21221000111001 is a wasteful number, since it uses less digits than its factorization.

21221000111001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1989861.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21221000111001 its reverse (10011100012212), we get a palindrome (31232100123213).

The spelling of 21221000111001 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred eleven thousand, one".