210505901 has 2 divisors, whose sum is σ = 210505902. Its totient is φ = 210505900.

The previous prime is 210505879. The next prime is 210505943. The reversal of 210505901 is 109505012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 113955625 + 96550276 = 10675^2 + 9826^2 .

It is a cyclic number.

It is not a de Polignac number, because 210505901 - 2⁶ = 210505837 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210505961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105252950 + 105252951.

It is an arithmetic number, because the mean of its divisors is an integer number (105252951).

Almost surely, 2^210505901 is an apocalyptic number.

It is an amenable number.

210505901 is a deficient number, since it is larger than the sum of its proper divisors (1).

210505901 is an equidigital number, since it uses as much as digits as its factorization.

210505901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 450, while the sum is 23.

The square root of 210505901 is about 14508.8214890114. The cubic root of 210505901 is about 594.8691198134.

The spelling of 210505901 in words is "two hundred ten million, five hundred five thousand, nine hundred one".