21001020111222 has 16 divisors (see below), whose sum is σ = 42213105753600. Its totient is φ = 6965162448552.

The previous prime is 21001020111191. The next prime is 21001020111277. The reversal of 21001020111222 is 22211102010012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8794395838 + ... + 8794398225.

It is an arithmetic number, because the mean of its divisors is an integer number (2638319109600).

Almost surely, 2^{21001020111222} is an apocalyptic number.

21001020111222 is an abundant number, since it is smaller than the sum of its proper divisors (21212085642378).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21001020111222 is a wasteful number, since it uses less digits than its factorization.

21001020111222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17588794267.

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

Adding to 21001020111222 its reverse (22211102010012), we get a palindrome (43212122121234).

The spelling of 21001020111222 in words is "twenty-one trillion, one billion, twenty million, one hundred eleven thousand, two hundred twenty-two".