221021001011 has 4 divisors (see below), whose sum is σ = 221023555800. Its totient is φ = 221018446224.

The previous prime is 221021000969. The next prime is 221021001031. The reversal of 221021001011 is 110100120122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221021001011 - 2¹⁸ = 221020738867 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221021000983 and 221021001001.

It is not an unprimeable number, because it can be changed into a prime (221021001031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1142906 + ... + 1322223.

It is an arithmetic number, because the mean of its divisors is an integer number (55255888950).

Almost surely, 2^221021001011 is an apocalyptic number.

221021001011 is a deficient number, since it is larger than the sum of its proper divisors (2554789).

221021001011 is an equidigital number, since it uses as much as digits as its factorization.

221021001011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2554788.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 221021001011 its reverse (110100120122), we get a palindrome (331121121133).

The spelling of 221021001011 in words is "two hundred twenty-one billion, twenty-one million, one thousand, eleven".