21110002011 has 24 divisors (see below), whose sum is σ = 34997844960. Its totient is φ = 12011078016.

The previous prime is 21110001949. The next prime is 21110002051. The reversal of 21110002011 is 11020001112.

It is a happy number.

It is not a de Polignac number, because 21110002011 - 2⁶ = 21110001947 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21110001984 and 21110002002.

It is not an unprimeable number, because it can be changed into a prime (21110002051) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 704376 + ... + 733733.

It is an arithmetic number, because the mean of its divisors is an integer number (1458243540).

Almost surely, 2^21110002011 is an apocalyptic number.

21110002011 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21110002011 is a deficient number, since it is larger than the sum of its proper divisors (13887842949).

21110002011 is a wasteful number, since it uses less digits than its factorization.

21110002011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1438355 (or 1438352 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21110002011 its reverse (11020001112), we get a palindrome (32130003123).

The spelling of 21110002011 in words is "twenty-one billion, one hundred ten million, two thousand, eleven".