21211220011 has 8 divisors (see below), whose sum is σ = 22215733920. Its totient is φ = 20213563392.

The previous prime is 21211219973. The next prime is 21211220021. The reversal of 21211220011 is 11002211212.

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 21211220011 - 2⁹ = 21211219499 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211219973 and 21211220000.

It is not an unprimeable number, because it can be changed into a prime (21211220021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1707990 + ... + 1720363.

It is an arithmetic number, because the mean of its divisors is an integer number (2776966740).

Almost surely, 2^21211220011 is an apocalyptic number.

21211220011 is a deficient number, since it is larger than the sum of its proper divisors (1004513909).

21211220011 is a wasteful number, since it uses less digits than its factorization.

21211220011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3428645.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21211220011 its reverse (11002211212), we get a palindrome (32213431223).

The spelling of 21211220011 in words is "twenty-one billion, two hundred eleven million, two hundred twenty thousand, eleven".