21111121201 has 16 divisors (see below), whose sum is σ = 21898356480. Its totient is φ = 20338496640.

The previous prime is 21111121183. The next prime is 21111121211. The reversal of 21111121201 is 10212111112.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21111121201 - 2⁹ = 21111120689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21111121211) 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, 1604616 + ... + 1617718.

It is an arithmetic number, because the mean of its divisors is an integer number (1368647280).

Almost surely, 2^21111121201 is an apocalyptic number.

It is an amenable number.

21111121201 is a deficient number, since it is larger than the sum of its proper divisors (787235279).

21111121201 is a wasteful number, since it uses less digits than its factorization.

21111121201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13656.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21111121201 its reverse (10212111112), we get a palindrome (31323232313).

The spelling of 21111121201 in words is "twenty-one billion, one hundred eleven million, one hundred twenty-one thousand, two hundred one".