105131821 has 2 divisors, whose sum is σ = 105131822. Its totient is φ = 105131820.

The previous prime is 105131813. The next prime is 105131849. The reversal of 105131821 is 128131501.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88566921 + 16564900 = 9411^2 + 4070^2 .

It is a cyclic number.

It is not a de Polignac number, because 105131821 - 2³ = 105131813 is a prime.

It is a super-2 number, since 2×105131821² = 22105399573552082, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 105131792 and 105131801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (105131021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52565910 + 52565911.

It is an arithmetic number, because the mean of its divisors is an integer number (52565911).

Almost surely, 2^105131821 is an apocalyptic number.

It is an amenable number.

105131821 is a deficient number, since it is larger than the sum of its proper divisors (1).

105131821 is an equidigital number, since it uses as much as digits as its factorization.

105131821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 22.

The square root of 105131821 is about 10253.3809545925. The cubic root of 105131821 is about 471.9667412288.

The spelling of 105131821 in words is "one hundred five million, one hundred thirty-one thousand, eight hundred twenty-one".