81050201 has 2 divisors, whose sum is σ = 81050202. Its totient is φ = 81050200.

The previous prime is 81050191. The next prime is 81050209. The reversal of 81050201 is 10205018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80371225 + 678976 = 8965^2 + 824^2 .

It is a cyclic number.

It is not a de Polignac number, because 81050201 - 2¹⁴ = 81033817 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81050201.

It is not a weakly prime, because it can be changed into another prime (81050209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40525100 + 40525101.

It is an arithmetic number, because the mean of its divisors is an integer number (40525101).

Almost surely, 2^81050201 is an apocalyptic number.

It is an amenable number.

81050201 is a deficient number, since it is larger than the sum of its proper divisors (1).

81050201 is an equidigital number, since it uses as much as digits as its factorization.

81050201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 81050201 is about 9002.7885124555. The cubic root of 81050201 is about 432.7642382753.

Adding to 81050201 its reverse (10205018), we get a palindrome (91255219).

The spelling of 81050201 in words is "eighty-one million, fifty thousand, two hundred one".