105212561 has 2 divisors, whose sum is σ = 105212562. Its totient is φ = 105212560.

The previous prime is 105212539. The next prime is 105212563. The reversal of 105212561 is 165212501.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 99600400 + 5612161 = 9980^2 + 2369^2 .

It is a cyclic number.

It is not a de Polignac number, because 105212561 - 2¹⁴ = 105196177 is a prime.

It is a super-2 number, since 2×105212561² = 22139365984357442, which contains 22 as substring.

Together with 105212563, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is equal to p_6044261 and since 105212561 and 6044261 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (105212563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52606280 + 52606281.

It is an arithmetic number, because the mean of its divisors is an integer number (52606281).

Almost surely, 2^105212561 is an apocalyptic number.

It is an amenable number.

105212561 is a deficient number, since it is larger than the sum of its proper divisors (1).

105212561 is an equidigital number, since it uses as much as digits as its factorization.

105212561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 105212561 is about 10257.3174368350. The cubic root of 105212561 is about 472.0875319445.

The spelling of 105212561 in words is "one hundred five million, two hundred twelve thousand, five hundred sixty-one".