221021121001081 has 2 divisors, whose sum is σ = 221021121001082. Its totient is φ = 221021121001080.

The previous prime is 221021121001063. The next prime is 221021121001141. The reversal of 221021121001081 is 180100121120122.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 189095061401856 + 31926059599225 = 13751184^2 + 5650315^2 .

It is a cyclic number.

It is not a de Polignac number, because 221021121001081 - 2²¹ = 221021118903929 is a prime.

It is a super-2 number, since 2×221021121001081² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221021121001981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510560500540 + 110510560500541.

It is an arithmetic number, because the mean of its divisors is an integer number (110510560500541).

Almost surely, 2^{221021121001081} is an apocalyptic number.

It is an amenable number.

221021121001081 is a deficient number, since it is larger than the sum of its proper divisors (1).

221021121001081 is an equidigital number, since it uses as much as digits as its factorization.

221021121001081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 22.

The spelling of 221021121001081 in words is "two hundred twenty-one trillion, twenty-one billion, one hundred twenty-one million, one thousand, eighty-one".