21111043213 has 16 divisors (see below), whose sum is σ = 23297578416. Its totient is φ = 19005212160.

The previous prime is 21111043153. The next prime is 21111043223. The reversal of 21111043213 is 31234011112.

It can be written as a sum of positive squares in 8 ways, for example, as 3618864649 + 17492178564 = 60157^2 + 132258^2 .

It is not a de Polignac number, because 21111043213 - 2¹³ = 21111035021 is a prime.

It is a super-2 number, since 2×21111043213² (a number of 21 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 (21111043223) 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 15 ways as a sum of consecutive naturals, for example, 2176731 + ... + 2186407.

It is an arithmetic number, because the mean of its divisors is an integer number (1456098651).

Almost surely, 2^21111043213 is an apocalyptic number.

It is an amenable number.

21111043213 is a deficient number, since it is larger than the sum of its proper divisors (2186535203).

21111043213 is a wasteful number, since it uses less digits than its factorization.

21111043213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13824.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 21111043213 its reverse (31234011112), we get a palindrome (52345054325).

The spelling of 21111043213 in words is "twenty-one billion, one hundred eleven million, forty-three thousand, two hundred thirteen".