21001211120111 has 16 divisors (see below), whose sum is σ = 22019089270464. Its totient is φ = 19992234096384.

The previous prime is 21001211120089. The next prime is 21001211120137. The reversal of 21001211120111 is 11102111210012.

It is not a de Polignac number, because 21001211120111 - 2¹⁴ = 21001211103727 is a prime.

It is a super-2 number, since 2×21001211120111² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001211120411) 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, 3536741 + ... + 7383153.

It is an arithmetic number, because the mean of its divisors is an integer number (1376193079404).

Almost surely, 2^{21001211120111} is an apocalyptic number.

21001211120111 is a deficient number, since it is larger than the sum of its proper divisors (1017878150353).

21001211120111 is a wasteful number, since it uses less digits than its factorization.

21001211120111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3847570.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21001211120111 its reverse (11102111210012), we get a palindrome (32103322330123).

It can be divided in two parts, 21001 and 211120111, that added together give a palindrome (211141112).

The spelling of 21001211120111 in words is "twenty-one trillion, one billion, two hundred eleven million, one hundred twenty thousand, one hundred eleven".