221012221111621 has 2 divisors, whose sum is σ = 221012221111622. Its totient is φ = 221012221111620.

The previous prime is 221012221111609. The next prime is 221012221111631. The reversal of 221012221111621 is 126111122210122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 220780638798721 + 231582312900 = 14858689^2 + 481230^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221012221111621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221012221111631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110506110555810 + 110506110555811.

It is an arithmetic number, because the mean of its divisors is an integer number (110506110555811).

Almost surely, 2^{221012221111621} is an apocalyptic number.

It is an amenable number.

221012221111621 is a deficient number, since it is larger than the sum of its proper divisors (1).

221012221111621 is an equidigital number, since it uses as much as digits as its factorization.

221012221111621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 25.

Adding to 221012221111621 its reverse (126111122210122), we get a palindrome (347123343321743).

The spelling of 221012221111621 in words is "two hundred twenty-one trillion, twelve billion, two hundred twenty-one million, one hundred eleven thousand, six hundred twenty-one".