21621212225101 has 2 divisors, whose sum is σ = 21621212225102. Its totient is φ = 21621212225100.

The previous prime is 21621212225077. The next prime is 21621212225113. The reversal of 21621212225101 is 10152221212612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12397229740900 + 9223982484201 = 3520970^2 + 3037101^2 .

It is a cyclic number.

It is not a de Polignac number, because 21621212225101 - 2³¹ = 21619064741453 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21621212225101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21621212225141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10810606112550 + 10810606112551.

It is an arithmetic number, because the mean of its divisors is an integer number (10810606112551).

Almost surely, 2^{21621212225101} is an apocalyptic number.

It is an amenable number.

21621212225101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21621212225101 is an equidigital number, since it uses as much as digits as its factorization.

21621212225101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1920, while the sum is 28.

Adding to 21621212225101 its reverse (10152221212612), we get a palindrome (31773433437713).

The spelling of 21621212225101 in words is "twenty-one trillion, six hundred twenty-one billion, two hundred twelve million, two hundred twenty-five thousand, one hundred one".