21112123011 has 32 divisors (see below), whose sum is σ = 34163811840. Its totient is φ = 11327952384.

The previous prime is 21112123007. The next prime is 21112123051. The reversal of 21112123011 is 11032121112.

It is not a de Polignac number, because 21112123011 - 2² = 21112123007 is a prime.

It is a super-2 number, since 2×21112123011² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21112123051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 189040 + ... + 279213.

It is an arithmetic number, because the mean of its divisors is an integer number (1067619120).

Almost surely, 2^21112123011 is an apocalyptic number.

21112123011 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21112123011 is a deficient number, since it is larger than the sum of its proper divisors (13051688829).

21112123011 is a wasteful number, since it uses less digits than its factorization.

21112123011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468395.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21112123011 its reverse (11032121112), we get a palindrome (32144244123).

The spelling of 21112123011 in words is "twenty-one billion, one hundred twelve million, one hundred twenty-three thousand, eleven".