90900001 has 4 divisors (see below), whose sum is σ = 90954900. Its totient is φ = 90845104.

The previous prime is 90899989. The next prime is 90900041. The reversal of 90900001 is 10000909.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10000909 = 179 ⋅55871.

It can be written as a sum of positive squares in 2 ways, for example, as 58920976 + 31979025 = 7676^2 + 5655^2 .

It is a cyclic number.

It is not a de Polignac number, because 90900001 - 2¹⁷ = 90768929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90900041) 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 in 3 ways as a sum of consecutive naturals, for example, 24886 + ... + 28303.

It is an arithmetic number, because the mean of its divisors is an integer number (22738725).

Almost surely, 2^90900001 is an apocalyptic number.

It is an amenable number.

90900001 is a deficient number, since it is larger than the sum of its proper divisors (54899).

90900001 is a wasteful number, since it uses less digits than its factorization.

90900001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54898.

The product of its (nonzero) digits is 81, while the sum is 19.

The square root of 90900001 is about 9534.1492016855. The cubic root of 90900001 is about 449.6293260280.

The spelling of 90900001 in words is "ninety million, nine hundred thousand, one".