21011221021011 has 32 divisors (see below), whose sum is σ = 30536367106560. Its totient is φ = 12772979610624.

The previous prime is 21011221021001. The next prime is 21011221021013. The reversal of 21011221021011 is 11012012211012.

It is a happy number.

It is not a de Polignac number, because 21011221021011 - 2⁴² = 16613174509907 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21011221021013) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34192170 + ... + 34801248.

It is an arithmetic number, because the mean of its divisors is an integer number (954261472080).

Almost surely, 2^{21011221021011} is an apocalyptic number.

21011221021011 is a deficient number, since it is larger than the sum of its proper divisors (9525146085549).

21011221021011 is a wasteful number, since it uses less digits than its factorization.

21011221021011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 619835.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21011221021011 its reverse (11012012211012), we get a palindrome (32023233232023).

The spelling of 21011221021011 in words is "twenty-one trillion, eleven billion, two hundred twenty-one million, twenty-one thousand, eleven".