21122111213 has 8 divisors (see below), whose sum is σ = 24145218240. Its totient is φ = 18100419840.

The previous prime is 21122111209. The next prime is 21122111221. The reversal of 21122111213 is 31211122112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21122111213 - 2² = 21122111209 is a prime.

It is a super-2 number, since 2×21122111213² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21122111191 and 21122111200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122111293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 321743 + ... + 381788.

It is an arithmetic number, because the mean of its divisors is an integer number (3018152280).

Almost surely, 2^21122111213 is an apocalyptic number.

It is an amenable number.

21122111213 is a deficient number, since it is larger than the sum of its proper divisors (3023107027).

21122111213 is an equidigital number, since it uses as much as digits as its factorization.

21122111213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 707827.

The product of its digits is 48, while the sum is 17.

Adding to 21122111213 its reverse (31211122112), we get a palindrome (52333233325).

The spelling of 21122111213 in words is "twenty-one billion, one hundred twenty-two million, one hundred eleven thousand, two hundred thirteen".