100206521 has 2 divisors, whose sum is σ = 100206522. Its totient is φ = 100206520.

The previous prime is 100206511. The next prime is 100206541. The reversal of 100206521 is 125602001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87703225 + 12503296 = 9365^2 + 3536^2 .

It is a cyclic number.

It is not a de Polignac number, because 100206521 - 2¹⁴ = 100190137 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 100206521.

It is not a weakly prime, because it can be changed into another prime (100206511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50103260 + 50103261.

It is an arithmetic number, because the mean of its divisors is an integer number (50103261).

Almost surely, 2^100206521 is an apocalyptic number.

It is an amenable number.

100206521 is a deficient number, since it is larger than the sum of its proper divisors (1).

100206521 is an equidigital number, since it uses as much as digits as its factorization.

100206521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 100206521 is about 10010.3207241327. The cubic root of 100206521 is about 464.4781921713.

Adding to 100206521 its reverse (125602001), we get a palindrome (225808522).

The spelling of 100206521 in words is "one hundred million, two hundred six thousand, five hundred twenty-one".