900090161 has 2 divisors, whose sum is σ = 900090162. Its totient is φ = 900090160.

The previous prime is 900090151. The next prime is 900090181. The reversal of 900090161 is 161090009.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 525280561 + 374809600 = 22919^2 + 19360^2 .

It is a cyclic number.

It is not a de Polignac number, because 900090161 - 2¹⁰ = 900089137 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 900090161.

It is not a weakly prime, because it can be changed into another prime (900090131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 450045080 + 450045081.

It is an arithmetic number, because the mean of its divisors is an integer number (450045081).

Almost surely, 2^900090161 is an apocalyptic number.

It is an amenable number.

900090161 is a deficient number, since it is larger than the sum of its proper divisors (1).

900090161 is an equidigital number, since it uses as much as digits as its factorization.

900090161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 900090161 is about 30001.5026457009. The cubic root of 900090161 is about 965.5216240803.

The spelling of 900090161 in words is "nine hundred million, ninety thousand, one hundred sixty-one".