9999090901 has 2 divisors, whose sum is σ = 9999090902. Its totient is φ = 9999090900.

The previous prime is 9999090883. The next prime is 9999090943. The reversal of 9999090901 is 1090909999.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9969822801 + 29268100 = 99849^2 + 5410^2 .

It is a cyclic number.

It is not a de Polignac number, because 9999090901 - 2²¹ = 9996993749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9999090961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4999545450 + 4999545451.

It is an arithmetic number, because the mean of its divisors is an integer number (4999545451).

Almost surely, 2^9999090901 is an apocalyptic number.

It is an amenable number.

9999090901 is a deficient number, since it is larger than the sum of its proper divisors (1).

9999090901 is an equidigital number, since it uses as much as digits as its factorization.

9999090901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 531441, while the sum is 55.

The square root of 9999090901 is about 99995.4544016877. The cubic root of 9999090901 is about 2154.3694015726.

The spelling of 9999090901 in words is "nine billion, nine hundred ninety-nine million, ninety thousand, nine hundred one".