90200081 has 2 divisors, whose sum is σ = 90200082. Its totient is φ = 90200080.

The previous prime is 90200057. The next prime is 90200093. The reversal of 90200081 is 18000209.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70980625 + 19219456 = 8425^2 + 4384^2 .

It is an emirp because it is prime and its reverse (18000209) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 90200081 - 2⁶ = 90200017 is a prime.

It is a super-2 number, since 2×90200081² = 16272109224813122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (90200281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45100040 + 45100041.

It is an arithmetic number, because the mean of its divisors is an integer number (45100041).

Almost surely, 2^90200081 is an apocalyptic number.

It is an amenable number.

90200081 is a deficient number, since it is larger than the sum of its proper divisors (1).

90200081 is an equidigital number, since it uses as much as digits as its factorization.

90200081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 90200081 is about 9497.3723208054. The cubic root of 90200081 is about 448.4723192160.

The spelling of 90200081 in words is "ninety million, two hundred thousand, eighty-one".