221131010120021 has 4 divisors (see below), whose sum is σ = 221131622055372. Its totient is φ = 221130398184672.

The previous prime is 221131010120003. The next prime is 221131010120063. The reversal of 221131010120021 is 120021010131122.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 66090883936900 + 155040126183121 = 8129630^2 + 12451511^2 .

It is a cyclic number.

It is not a de Polignac number, because 221131010120021 - 2²² = 221131005925717 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221131010120081) 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 3 ways as a sum of consecutive naturals, for example, 305425310 + ... + 306148463.

It is an arithmetic number, because the mean of its divisors is an integer number (55282905513843).

Almost surely, 2^{221131010120021} is an apocalyptic number.

It is an amenable number.

221131010120021 is a deficient number, since it is larger than the sum of its proper divisors (611935351).

221131010120021 is an equidigital number, since it uses as much as digits as its factorization.

221131010120021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611935350.

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

Adding to 221131010120021 its reverse (120021010131122), we get a palindrome (341152020251143).

The spelling of 221131010120021 in words is "two hundred twenty-one trillion, one hundred thirty-one billion, ten million, one hundred twenty thousand, twenty-one".