100222561 has 2 divisors, whose sum is σ = 100222562. Its totient is φ = 100222560.

The previous prime is 100222559. The next prime is 100222567. The reversal of 100222561 is 165222001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58232161 + 41990400 = 7631^2 + 6480^2 .

It is a cyclic number.

It is not a de Polignac number, because 100222561 - 2¹ = 100222559 is a prime.

Together with 100222559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (100222567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50111280 + 50111281.

It is an arithmetic number, because the mean of its divisors is an integer number (50111281).

Almost surely, 2^100222561 is an apocalyptic number.

It is an amenable number.

100222561 is a deficient number, since it is larger than the sum of its proper divisors (1).

100222561 is an equidigital number, since it uses as much as digits as its factorization.

100222561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 100222561 is about 10011.1218652057. The cubic root of 100222561 is about 464.5029737678.

Adding to 100222561 its reverse (165222001), we get a palindrome (265444562).

The spelling of 100222561 in words is "one hundred million, two hundred twenty-two thousand, five hundred sixty-one".