103205021 has 2 divisors, whose sum is σ = 103205022. Its totient is φ = 103205020.

The previous prime is 103204967. The next prime is 103205029. The reversal of 103205021 is 120502301.

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., 102292996 + 912025 = 10114^2 + 955^2 .

It is a cyclic number.

It is not a de Polignac number, because 103205021 - 2¹⁸ = 102942877 is a prime.

It is a super-2 number, since 2×103205021² = 21302552719220882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 103204987 and 103205005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (103205029) 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, 51602510 + 51602511.

It is an arithmetic number, because the mean of its divisors is an integer number (51602511).

Almost surely, 2^103205021 is an apocalyptic number.

It is an amenable number.

103205021 is a deficient number, since it is larger than the sum of its proper divisors (1).

103205021 is an equidigital number, since it uses as much as digits as its factorization.

103205021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60, while the sum is 14.

The square root of 103205021 is about 10158.9872034568. The cubic root of 103205021 is about 469.0656266944.

Adding to 103205021 its reverse (120502301), we get a palindrome (223707322).

The spelling of 103205021 in words is "one hundred three million, two hundred five thousand, twenty-one".