221031111021 has 16 divisors (see below), whose sum is σ = 348423427200. Its totient is φ = 121948198848.

The previous prime is 221031111019. The next prime is 221031111043. The reversal of 221031111021 is 120111130122.

It is not a de Polignac number, because 221031111021 - 2¹ = 221031111019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221031101021) 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 15 ways as a sum of consecutive naturals, for example, 181469926 + ... + 181471143.

It is an arithmetic number, because the mean of its divisors is an integer number (21776464200).

Almost surely, 2^221031111021 is an apocalyptic number.

221031111021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

221031111021 is a deficient number, since it is larger than the sum of its proper divisors (127392316179).

221031111021 is a wasteful number, since it uses less digits than its factorization.

221031111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362941108.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 221031111021 its reverse (120111130122), we get a palindrome (341142241143).

The spelling of 221031111021 in words is "two hundred twenty-one billion, thirty-one million, one hundred eleven thousand, twenty-one".